Your help is very much appreciated. I certainly don't want you to feel my frustration is directed towards you. ?
I'm going to get her to let me uninstall and reinstall it this weekend and see if it still persists.
I suspect we probably put the settings to 'allowed' when we first went through the app permissions when initially setting everything up (I don't remember as that was a couple of years ago). I would have just assumed it was for things like power saving modes, layouts etc on her phone. Not anything that we would have wanted to stop her doing.
Anyway, I'm going to try reinstalling it and if it doesn't work I'll get the information suggested and come back to you. Thank you again for trying to help us work this out.