How are her poos? Is she still going normally? Is she drinking normally? You need to carefully monitor her food and water intake, and stool output carefully. I have one chin that all he does is sleep! I swear no matter what time it is if you go over to him he's sleeping. Then I have two that never sleep, and sometimes I'd sure like them too! LOL But they're always awake bouncing around their cage. So chins have different personalities, and your chin just might be one of the more laid back ones.
I'm sure some of the more experienced members on here will give you some better advice, but it gives you a place to start. Monitor the eating/drinking/poos, and let us know how those are. Also if you have a gram scale, start weighing her. Alot of problems with chins can be seen in their weights.
Hope that everything is ok.
Jacqui