What uni - well it depends and there are lots of factors.
With AAB she could get on to a less popular course at a reasonably well-rated uni - so maybe not Eng lit at Warwick but maybe at Birmingham or Newcastle? She should cross off Oxford, Cambridge, probably Imperial, LSE and UCL. But there will be courses even at Bristol and Durham that ask for AAB. MFL especially I suspect.
Does she want a campus uni with everything on site (Nottingham, Loughborough, Birmingham, Warwick, Lancaster) or more city-based one (Sheffield, Leeds, Leicester (tho it has a campus with halls and a separate campus with uni buildings), Bristol?
Does she want a big city (Manchester, Leeds, Brum) or a smaller place (Warwick, Lboro, Canterbury, Durham)?
Does she want to be near home or further afield?
Is cost an issue? If so accommodation (broadly speaking) is cheaper in the north than in the south (with some exceptions) - so a house share in Leeds is cheaper than one in Bristol.
I think the key is to consider what courses she would enjoy, then consider some of the factors above (and any others than may be relevant - close to sea? in countryside?) and then look at where her AAB might get her. Open days this summer are a good idea.