My girl could roll to her side after mere days earthside, and could also hold her head up with surprising strength right away! Rolling over as a mileston however means rolling from their back all the way over to their stomach, and vice versa from stomach over to their back, which is on average achieved around 5 months of age. My girl did both around 2 months, was sitting up at 4 months without support, crawling at 5 months, pulling to a stand at 6 and walking along furniture days after. She's about to turn 10 months tomorrow and although she has taken a few independent steps herself since before 9 months, she hasn't started walking fully yet....she takes a step or two without holding on once then NOTHIN for a while haha she is stubborn! Anyways my point is, if your kid is early on milestones prepare for lots of falls and bumps, and don't expect them to stay on a roll forever with being early, because they honestly do what they want when they want hahaha I learned that the hard way!

My second did that! He hated sleeping on his back and would turn to his side