Literally took my girl less than a week to roll from back to front both ways and from front to back...... She started one day my rolling onto side, next day she could get on front, by same afternoon got onto front and learnt how to get arm out and then could push front end up! Following day she was able to then roll from back to front and back again Then a few days later rolling from back to front the other way! That was a few weeks back and now she is getting her bum up and able to go into her knees so hoping it wont be too long before we have a crawler!