ok....she is trying to roll over and wen i will push she will bent and she is holding her head

Hello Monika, usually babies turn by 3-4 months. Allow your baby to be on the bed but not very soft bed. Thus will help baby to turn, when he/she is ready

If baby is holding head up steadily, she will probably roll over soon. Everyday give her some tummy time so that her neck and back muscles get stronger.

my daughter has not yet started....i am a little worried.

Ideally 2.5-3, dey shd start wid tummy time... Bt its purely individual wid kids to kids.