DS wouldnt do tummy time until roughly 4 months of age and honestly it hasnt made a difference to his development. Hes starting to shuffle (calling it crawling would be too generous lol) and can now hold his head up for over 20 minutes at a time. I didnt stress too much but if youre really worried I suggest having her lay on your belly so she can see you and know shes safe. Theyre better with that than on the floor HTH