The Q does seem rather perfect. I had (although I believe when I was older than 8, like middleschool) a Pentax Auto100. The Q is the spiritual successor to that one, although the Q is not nearly as simple to operate.
Does she take good enough care of the Olympus to trust her with the more valuable one, like a Q? Is she currently "borrowing" the Olympus and using it sometimes, or actually taking care of it and putting it away herself? If not, perhaps stepping up to that with the Olympus is a good next move.
I'm decades older than her, and frankly there are some nice things I don't trust myself to take out and play with, or to take care of properly long term. I can't remember being 8 specifically, but i think there was a good chance I might lose or break things back then. Why, in fact, I almost walked away without my nice pair of stabilized binoculars the other day at a baseball game...
It won't surprise me if your eight year old is more responsible than me, though, and that shouldn't really affect your decision either way