JaneL is right - it's not so much about doing dance, it's more about choreography & reviewing dancing - which is exactly what my vocationally trained son hated about it . He just wants to dance (ballet) - he really, really doesn't care about anything else.
However, if your daughter is interested in teaching, or performing generally, GCSE dance would be a great option for her (it's good to do subjects you really enjoy at GCSE if you can), however, as a parent of two other "academic" children, I would have discouraged them from doing dance GCSE if it meant missing out on other important subjects at school (my daughter didn't want to do it despite doing a lot of dancing outside of school - she also loves to dance, but hates choreography and writing reviews, learning about the history - I must've done something wrong...).