Check her carefully, if her intestines are prolaps, the vet will need to work on that. If there is an animal emergency hospital, I would call them and make sure there is someone there that has worked with chinchillas. A chinchilla can be easily overdosed when put to sleep if the vet does not know that much about them. I would also be very concerned about the kits, should the momma have to be taken to surgery.
There is always a possibility that it could be hemorrhoids if she is straining/trying to deliver a kit that is to large or that is not in the correct position.
If she is not bleeding, you may be best just to wait and see ... unless you can get her to a knowledgeable vet. Triple antibiotic ointment can be used in the area around the rectum to keep it soft and help with any bacteria. IF it is vaginal bleeding, she needs a vet a.s.a.p.
Is she still straining? (From labor or the rear end.)
When is her due date?
Jo Ann