Get your DD to have a look at the s hooks of architecture listed here, to see what their requirements are:
http://www.arb.org.uk/student-information/schools-institutions-architecture/To qualify as an architect, she would need to obtain qualifications in Parts I, II and III - Part I exemption comes automatically with a first degree from any of the institutions on the ARB list.
With regard to Art, it does help if she has a ability, even if not taking the A level. Most universities require a portfolio as part of their assessment process.
Bath's course is very 'engineering-y', The Bartlett (UCL) very 'arty'.
TSR has quite a lot of chat about Architecture (with plenty of posts by 'grown ups' such as ''PQ'. Look in
https://www.thestudentroom.co.uk/showthread.php?t=2022808, for example.
(DS2 wanted to do Architecture for ages, then a couple of months ago changed his mind and now wants to do History of Art

).