Hello doctor, My baby is now 7 months 26 days old , till now she has not tried roll over and when I lie her on stomach she won't stay in that position more than 5 sec and immediately turns on her back position .But she started to sit without support n plays with toys ....Is it normal that still not rolling over n not crawling ?? some says few babies skip crawling n rolling over ,directly starts to stand n walk . Is it TRUE?