As she’s as premmie bub we go by corrected age. At 6-7 months all babies go through a big development change physically, mentally and most importantly emotionally. This is when your baby completely falls in love with you. She knows you’re her mum (and dad) and when you’re gone she misses you and wants you to come back. This is your attachment-bond. This means her brain is growing as well and she is starting to understand her world better. Physically she is moving around more and so can more easily wake herself. All these changes disrupt her sleep and sometimes premmie babies have less ability to manage these disruptions to their sleep patterns. She needs you to gently support her with a soothing, consistent bedtime routine (day and night) and gentle re-settling strategies when she awakens between her short sleep cycles. If she gets distressed, don’t keep trying, get her up and try again for her next sleep when you see she gets drowsy and sleepy. Hope that helps.