I transferred Jesse from a wrap to a sleeping bag at around 8 weeks i think. He was always getting out of them and was getting to big for the wraps i used. I just put him straight in the sleeping bag one night and he was fine.. though in saying that, he would always sleep during the day with just a blanket over him, not wrapped, so he was kinda use to having his arms out sometimes while sleeping. You could purhaps start using the sleeping bags during the day to get her use to having her arms free while sleeping and then eventually use them at night too. For us the sleeping bags are great as Jesse likes to pull blankets over his face when he's tired!