What should be O2 saturation % in babies?

[Himavissa]

My lo was born 10 weeks early and she came home on o2 monitor. Since its been 4 months she is home we were asked to wean off oxygen slowly. I usually wean her off all day. Today as i want to check the sats it was 96/118. Is this a good sat level? We are yet to do a sleep study. She sleeps sometimes she turns..when she sleeps on side it is 97 % . Also she has silent reflux. Does she need oxygen still with these,levels?