Thank you for your replies everybody.
Working backwards, while ideal, won't work with DD. She has no idea what she'd like to do. The very fact of having to choose is very stressful for her and she is young for her age (there are some SEN involved).
Another specific consideration is that we are looking at college as a blank slate to improve her confidence and undo the damage secondary school has done to her mental health. While at the same time trying to plan for the future if she recovers well enough and wants to go to uni. No pressure 😁.
Now for the purely academic side -
I hear you on the most colleges not doing 4 A levels anymore. However, DD would really benefit from at least starting 4 then dropping 1 as she is very unsure.
The issue is neither of the two colleges she has applied to are letting her put 4 down in her application. One has said she can try all on taster day, but that's not until June/July and she feels stuck not knowing for sure if she'll be allowed to take one of them. She was talked into dropping maths at interview (for similar reasons to what @clary , @Octavia64 and @RafaistheKingofClay give). But she regretted it straight away!
@Needanadultgapyear , music is non-negotiable because it's the only thing that kept her in school for the last 2 years and not drop out. That's the only thing she is sure about.
@Octavia64 and @Foxesandsquirrels , can I ask why you say Maths does not keep options open? DD has expressed some interest in very disparate things - Agricultural land management, Sound Engineering, Phsychology, Data Analysis... Would Maths not be useful for those? And French, English and Music preclude the first two?
Octavia64, can Music be consiered an essay subject at A level? In which case, maybe she could drop English Lit.
Interesting what you say about Maths being easier to pick up outside school Foxandsquirrels.
@clary and @SlightlyJaded , here is an daft question (I was not educated in the UK ) - Why does the amount of native French speakers impact on everybody's grades? Is it that there is a finite amount of grade A* to give, rather then it being awared to everybody who achieves the required level?
French is her best subject.