Baby doesn’t like to roll over?

Is it ok if baby doesn‘t like to roll over from front to back?

This has been her timeline:

2.5 Months - rolled from front to back for the first time and did it occasionally for a little while

2.5-4 Months - didn’t roll over much

4 Months - rolled from back to front for the first time, but then stopped rolling for awhile, preferred to be held in a standing position and bounce

4.5 Months-now (5 Months) - rolls over from back to front all the time, but never rolls from front to back

Should I be concerned? Is there a way to encourage her to roll from front to back?