• One does not require any specific degree to be employable (technically).  The awkward thing is that as juniors in an office, at first, it's likely a fresh Barch or March will be given the same tasks as a college technologist (and paid the same)... and unless your daughter can hold a p.eng stamp following the arch-eng bachelors, it is unlikely that that will be her first gig.
• Architectural engineering paths are often more technical than design oriented. Something to consider since you need a very good control of both to succeed in this profession.
• Consider your location's requirement for architects and if the programs are accredited.
• Pick a school based on more than just reputation.  Cost is a big factor and no architecture degree is worth 6-figure student debt.  Most schools have open house events.  Go to them (well, make your daughter go to them) and see for yourself what the student workload is like.  Architecture school is very tough compared to typical university courses (and is in no way close to highschool... double that for those A-level students) and the working world is no different.

I would look into getting a plain vanilla civil engineering degree with a concentration in structures. Large CE firms go out of their way to recruit young women graduates and they have the means to offer substantial starting salaries. After working for a couple of years she might, or might not, want to get a two year Master's degree in architecture. The CE curriculum is demanding enough; your daughter needs a well-rounded college experience as well so I would forget the double major. Just my two cents.

An architectural engineering degree will lead to an engineering career; if she wants to genuinely be both an architect and engineer, then the double major is the way to go. If her primary interest is architecture, and her interest in engineering is only to better inform her architectural work (an admirable desire), then a full double major is probably overkill.

She will definitely be just as employable with a B.Arch as she would with an M.Arch. (As Non Sequitur noted, she could also be employable with only a technical school AA, or no degree at all, but, speaking as someone who took that path, I wouldn't recommend it.)

There are "rankings" of architecture schools out there, but I would recommend going deeper and finding out specifics about the programs and finding one that aligns with her interests. While having a "prestige" degree might give her some more opportunities in her early career, any accredited degree will make her employable, and after a few years proving her abilities in the real world, most people won't care what school she graduated from.

If she is truly exceptional, I'm hoping she is doing this research for herself.  She really needs to know what path she wants to take.  Once in architecture school, it's hard to change into a new major without some major backtracking.  That's likely an additional expense.  So, She needs to know going in what the route is.  

I personally think it's hard enough keeping up with what I have to know on a project (which includes a decent understanding of the engineering side to keep things coordinated).  I don't think I'd have time to do both the structural work on a project and the architectural, without backing down the total number of projects.  I can be more profitable turning out Arch work than trying to do both.  

If she wants to do her own gig, and keep everything in house, the Arch engineering degree can be ok. But, she's going to need to work somewhere and get experience in both fields before getting either license.  So, you're talking years down the road before owning her own shop. Then she will also have to make sure she is getting adequate experience in both.  I'd be willing to be the instant she shows more aptitude with one of the two fields, the firm will push her into that particular role, taking away from her experience with the other... unless they are very committed to her getting licensed in both. 

If she wants to be an architect then she should focus on getting an accredited architecture degree and maybe a minor in engineering if she really wants it. In the US, architects are typically allowed to perform the engineering scope, at least up to a certain size of building. If she wants to do smaller projects, she can do the engineering as an architect. If she wants to work on larger projects, she likely wouldn’t have the time to also do the engineering. 

Stick to an accredited architecture degree if she wants to be an architect.  Look at the NCARB website (they, along with the state you practice in, control licensing if you are in the US) and see what all the steps are to actually becoming an architect.  That being said, you are employable in this profession with only an Associates, but you are prohibited in how far up the ladder you can go.  A Masters will get you licensed - except in a few states where it is not required - and able to own your own office.  See if there are any architects in your area that she could meet with for a coffee and discuss what the profession is like.  If she is truly interested, she could probably find someone to shadow.

I wouldn't be that concerned with rankings at this point.  The degree only matters so much in the field.  It's really about the work you produce.  That being said, a state school will probably be a good stepping stone to a much better graduate school, or help you land a job in a local firm.  An ivy or private school might get you to another ivy or private school for grad and help you land a similar job, but in a more prestigious firm.  It is very common to start at a state school and move up to a private or ivy for grad.  The more important thing is that she find a school that is a good fit for her, where she feels comfortable asking questions and learning.  Since it sounds like she is interested in engineering, maybe she looks for a program that is more practical oriented vs. more theoretical. Just an idea.  No matter what the school is - state, private, or ivy - double-check that it is an accredited program.

Architecture school is incredibly difficult; I know you're thinking "but she is brilliant!" And maybe she is, but the amount of work is absolutely ridiculous.  The profs do this to you on purpose.  It is not just about learning the material, but learning how to produce, make decisions, and problem solve.  If it is possible to go to some open houses and look at some student work, that would be ideal.  See if she can sit in on a few different classes and talk to some of the students about what their workload is like. 

She'll get enough experience with structural engineers in the field to not want to do any of that by herself. If she's interested in engineering, she could focus her education more on the digital side (ie. grasshopper) and work more with fabrication labs during school. The path I see for her would be a B.arch then a post-professional.

Top design firms out there work with the world's best structural engineering firms. If she ends up in one, she'll have plenty of time consulting with the best. 

As for rankings, check out design intelligence's undergraduate and graduate rankings. The schools at the top are generally considered the "best", but as always check out their websites and look at student work.

Bachelors in engineering, Masters in Arch is how I'd do that. My school would not allow double majors like that, not sure who does, did you find some? There are always going to be engineers that reject you for not being 100% committed to their field and archs will do the same. Might spend a lot of time and effort and end up too thin with nothing to show I stead of two things. Make sure to spend time in the industry interning/shadowing before investing too much time and effort. Archs and engineers don't necessarily get along, have quite different priorities. Archs oversee projects, take care of clients, engineers bang em out.

she should be doing this research herself for it to be meaningful. it's kind of you to help but if she doesn't care enough to examine the options herself she will struggle in school.

I've worked with several excellent facade engineers who had a background in architecture. there are niche areas of overlap for someone with deep interest in both fields, but it's not necessarily of any advantage for an architect to have this background. a few notable architects did study structural engineering, though it serves them maybe more as an inspiration than a practical skill. i'm thinking of jeannie gang and santiago calatrava.

take a look at some of the big midwestern public universities UIUC for example, where she could get some exposure to both and pursue this interest.

fwiw i had classmates dual major in b.arch and bs civil engineering; none of them really made use of both. engineering is not part of the day to day work of a typical architect. both fields require extensive work experience to make a valuable professional so it's only worthwhile if she has a real intent to make use of the combination.

encourage her to reach out to some local engineers and architects to visit their offices and learn about their work. i did this in high school and it helped give me some confidence about the direction i followed.

Accredited architecture program search: 

https://www.naab.org/architect...

Accredited architectural engineering programs list:

https://www.aeisdc.org/about/c...

Not much cross-over for specifically those two degree paths in terms of which schools offer both options. But civil engineering would work for her goals as well, architectural engineering is not as widespread as a specific program.

If you need help passing the Architectural Engineering PE Exam, here is a link to a study guide.  https://architecturalengineeri...