I think it is a good idea to visit DH again and to look at other schools where your DD may be happy. I would probably especially look at co-ed boarding schools as well.
With regards to WA, it is a great school but you would have to make sure it is right for your DD, even if you get an offer and sometimes WA tries to make that choice for you.
It is extremely competitive in all areas.
Several girls in year 7 have grade 8 on their instruments (some diplomas I think). In sports, again, some play various sports at a really high level. You can play for the A-team in your primary school and not make any of the teams at WA.
There is a lot of homework and if you aren’t well organised, “get” the concepts quickly and quite driven to keep striving for good grades - and resilient when you do badly- it seems very hard.
having said that, for a very competitive girl who want to play in an extremely challenging orchestra, play high level sports, being stretched academically and is confident enough not to be bothered by any extreme high achievers I cannot think of a better school.
DM me if you want more information.