[Ria P]

Hello and welcome to HC!

When Charli sits in her food bowl moving things around she may be pouching some food. Hamsters are very food orientated and like to hoard food so she may be doing that when you are asleep. Dwarves are so small and sometimes it looks like they haven't eaten anything because of the small amounts they eat.
If you are worried about her food intake you could weigh her every few days.

I'd avoid fruit and carrots but seeds, nuts and mealworms are good for treats. Brown linseeds are good for their fur and they love them. Mine love small bits of cucumber best.

I'm one of those people who strongly dislike hamster balls and feel sorry for any hamster trapped in one without sufficient ventilation and ways to communicate. Yes, they run in them but what else can they do. A secure play pen is much more fun for hamsters and humans. You could also start a family project and join cardboard boxes together with plastic bottles to make a hamster run and add a homemade maze with treats hidden.