Actually not all kids have learnt to roll back to front by 8mo, and of those who have, not all would be able to do it in a swaddle. I'm no expert, but everything I've read says that once they can roll in the swaddle, it's no longer safe, I'm afraid.
So you always keep the A times 2h - 2h 15, regardless of nap length? Apart from the one before the CN, of course? Tbh some early morning babbling is quite common at this age, it may be developmental or a sign that you need to start stretching A times during the day, gently. If the day's shifted completely then it's pretty much what she was doing before then, ie the night length hasn't changed significantly, so what you want to do is gently shift the whole day? It's good that she's going back to sleep afterwards herself
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Of course there's also the possibility of some OT which can also lead to EWs, but I'd probably expect some BT battles or early NWs and general crankiness during the day - do you get any of this?
I'm afraid though that I really do think you need to wean that swaddle now, so you'd expect things to get a bit wonky when you do that anyway, you may need to come back to this routine stuff once you've been through weaning and just do the best you can to keep OT at bay in the process
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Do you have sleeping bags you can use? These are a great transition, actually just great for most LOs regardless of whether they were swaddled. I'm not actually sure whether it's safe to wean one arm at a time when they're already rolling the props board may be better for that or someone else may pop on here... At this age we actually weaned more cold turkey - the swaddle we used allows you to swaddle with both arms out so that's what we did, then transitioned to a sleeping bag. It really wasn't as messy as we'd feared, yes she needed more help to settle at first but I think it's much easier at this age than when they're younger
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