Umm... I would say they should be fine. As long as they aren't already in the process of hatching. Meaning that they haven't piped yet. The mother usually gets off the nest about 15-30 mins a day. (unless you have a crazy broody like me who gets off 2 times a week! Hehe) so yes. I would say they should be fine. Good luck!
The first two weeks yes they will get up eat drink etc, but when it gets close to hatching time, they will not leave the nest. They will stay put until those babies are out..