I also wanted to say that sometimes I wear my HA all the time - other times I don't wear it at all. I have HL, as well as APD and sometimes no amount of volume will help me process sounds - but the volume/sounds will give me a headache/make it harder to focus. I look at my HA as a tool that helps me in some situations and doesn't in others.
The difficult thing for parents is that children go through all sorts of stages - it's weighing how much is "hearing" related, and how much is just "I don't want to". Clearly if your child made a fuss about refusing to wear shoes, or a jacket in the cold etc you'd still make them do it. In a lot of ways HAs with kids can be the same - it's not that they hate their HA, it's just that they've chosen that item to be their "control item" for a period of time.
I would make sure all her settings are correct, that everything is comfortable (mould, tubing length, etc) and talk to her about the specifics of why she's currently not wanting to wear it/them. As a HA user yourself it's a great chance to be "real" with her - explain that you too sometimes may find them frustrating, uncomfortable etc and then see if the two of you can find a solution that works (IE she wears them at school for classes, but can turn them off at lunch, breaks, and at certain times at home etc ...)
Work together to find a balance.