I shouldn’t be worried, should I?

My daughter is 19 weeks & 6 days (4 months) I can’t help but notice other babies her age hitting the “rolling-over milestone” & mine hasn’t showed interest or started trying to roll..?! I understand every baby will hit their milestones later than some, but I shouldn’t be too worried right?! If so, I would love for any helpful tips to encourage her.

On a side note, we’ve encouraged tummy time everyday since she was 2 1/2 months old. She hated it so we would only have her on her tummy for about 15 mins a day. Some days she would cry her head off and I’ll plop her back up with me and cut back on it. Not sure if that played a part in it 🤷🏽‍♀️ I guess I’m just concerned because everyone’s baby seems to be moving at the “suitable” pace than mine.