At 10.5 months I would be inclined to say that she should be fine to sleep on her belly. I know Aidyn was doing it by that age, and there wasnt much we could do about it! Perhaps keeping her arms free when she is wrapped, or introducing her to a grobag like sleeping bag will give you more peace of mind that she will be able to move freely if she gets stuck? She is getting to the age though where she'll be pretty good at wriggling her way around, so I wouldnt be too worried! I have heard that the greatest danger for SIDS risk is before 6 months.