Hi, I have just hatched 12 eggs a few days ago and they really hatched over a 3 day period. I did help the last 2 as they were taking too long I felt. I think as long as you can see/hear movement inside the remaining shells you should be ok, however, I have no problem with helping them along. I know many people tell you not to do this but it didn't cause any of mine any harm. All 12 are doing great. Good luck, let us know.
James