As an aside, your DD is probably feeling quite unsettled right now.
Like her, I did very well at GCSE (10xA, 1xA) -but then I started Physics, Chemistry, Maths, and Biology at A-Level - and got E*s in my AS levels.
That sense of 'failure' when I'd only know academic success was hard, and actually something that I later addressed in therapy.
I switched courses after my AS level results, and went to a local college (rather than the sixth form I'd been at) - and I went on to get 4xD at A-Level (humanities and arts subjects).
Again I'd 'failed' - looking back, I realise that the skillset required to pass GCSEs is very different than A-Levels, because I was bright, I'd never learned to 'study' I had no idea about repeatedly practicing the same thing, or doing additional reading, because I'd never had to.
So with my eight D-and-below AS/A Levels - I started as an intern in an ad agency.... they sponsored me through university, I got a 2:1 - and now (23 years later) - I'm in a leadership position in a tech company and love my job.
The road to success may not be linear - but what your DD is going through right now will shape her for the rest of her life, so tread with caution.