Tummy time problems

Joanna🎀 • Nanny, mommy to a 3 year old lil boy & a new little girl born 5/8/15
so I've been doing tummy time with my little miss daily since we got home (two months now) but she refuses to lift her head up or wiggle around. She has great head strength (I sit her up per the Peds suggestion) but she just wants to suck on her hand, the blanket or just go to sleep instead of working out. I've tried toys, getting down there with her, nothing will make her work her head muscles or make an effort to roll over. Does anybody have any suggestions?