Carl, I think it is worth trusting your, and more importantly your daughters, instincts.
It sort of happened organically for us. I'm sure few of DD's peers, or indeed teachers, realised how tough things were following her accident the previous summer. She comes across as very capable. However she was remarkably flat when she finally got the offer she really wanted. (17 applicants a place - so not something she expected.) I too was looking forward to her settled at University but was honestly not surprised when she announced she wanted to defer. After a year of keeping going, she just wanted time.
It seems easy for them to funnel straight into University. However there is no rush, and really this is the best time to explore options and interests. University can come later, and as long as they are engaged and active in the interim, they will probably be better students as a result of wider experiences. (There is some truth about education being wasted on the young...)
I suspect the world can look like quite a scary place from the perspective of a teenager. A lot of the later part of school years is about passing or failing. And it remains tough if you are aiming for competitive courses and competitive careers. More than a couple of DDs peers are struggling with anxiety whilst others seem to be avoiding adulthood continuing risky teenage behaviour such as parties/alcohol/drugs. (Not all parties are risky - obviously!)
Trying something different not only might work out, but could also remind her that she really does want to do something academic. And that it is worth trying something, as long as you are willing to fail and have a good plan B.
She wont be the only one juggling other things. Indeed a girl in DS' year ended up sitting an A level paper in Cannes, whilst there for the screening of a film she was in.
There again if she finds the prospect daunting, she does not need to do it.
I'm enjoying it. I don't worry nearly as much if she is home late, as I would not even know if she were at University. I no longer need to consider nagging about homework, but instead can join her watching Netflix, and she is doing a lot of cooking for us. It is probably the last time she will live at home, and so nice that the pressure is off.