I would first of all suggest you to read up on the breeding and babies section. I think they have the stickies from the CNQ site.
1-you need his vet number-and an after hours vet number if he has it
2-(hoping this is done already) be sure she is in a baby safe cage
3-if she does go into labor and has the babies while in your care, read up on hand feeding in case of an emergency and other baby care.
Hopefull you should be fine. Has he been couting down from 111? Is she due on one of the days you are with her???