Chinta looks well proportioned, not overweight. I've had another thought- as she is evidently the dominant female she is also likely to be the least stressed, so perhaps the most likely to conceive but does she still have any contact with the male?
She has lost some weight through being more active since Demo and Mali arrived. Mali is the dominant orang, followed by Chinta, then Demo and Gambira. She seems happy to submit to Mali and they get along well.
I haven't seen her with Demo for some time.
