My almost-8-month-old has recently started crawling and now keeps sitting up in the cot when we are trying to get her to sleep, either at bedtime or naps. We turn her back on to her back repeatedly and have to hold a hand on her stomach to stop her rolling over. Recently this has been taking up to an hour until she eventually falls asleep absolutely exhausted. Then she sits up again during the night and process starts again. My HV suggested it was overtiredness but have tried putting her down sooner and no difference. We cannot leave her alone in the cot as she cries and falls backwards, banging her head on the bars. I also don't want to do sleep training. Will this pass? Is it just the crawling causing it?