How long does hair/make-up really take??

I have myself, my mom, my MOH, and one BM getting ready with me. I have one hair and one make-up person. Both my mom and the BM will be getting a blow-out only.

How much time should I allow?? I know there will be crossover time (one person getting hair while another gets makeup) but will 3 hours be enough?? I don't want to be rushed, but don't want to get up at a a$$ crack of dawn for no reason!!!!

Thanks!!!!