Hi there, I agree that she's using you as a prop. If she calms down when you hold her but won't when she's laying down, that she obviously doesn't NEED food or anything, and just is using you to get her back to sleep. If you say she won't do it on her own when she sees you than she never will if you don't MAKE her. That will be the first toughest issue. If you want to nip this in the bud you have to make that decision and stick to it. The first time you do it she may not go back to sleep for even an hour or more. But if you don't give in one single time, she'll get the idea. But w/ a new baby coming you don't want to have to get up w/ her and be the one to have to put her back to sleep.
As for the wakeup, I agree w/ the same wakeup every day. Do whatever time you want her to wake up. If her biorythem is 9 am, that consistently try to get her to sleep till then. Or if she wake a couple time a week at 7:30 and won't go back to sleep, than do sometime in b/t like 8-8:30 and wake her. If she wakes at 9 and naps at 1, that's not too much awake time. That's only 4 hours and at 15 months that's fine for most kids. Many can do up to 5 or more at that age. And 6 hours before bed isn't too much either, I don't think. If that's what works for her than keep to it. I do think the nightwakings, especially the early am one is due to her wanting you to put her back to sleep. My son is 16 months and very rarely do we get a night where he doesn't cry out 2-3 times. I usually don't have to resettle, but occasionally do. So I personally would decide when I wanted wakeup to be, then stick to your current routine and try to fix the dependency thing first. That right there might be the true cause, and if that gets fixed her routine might stabilize. You could also try 15 min earlier bedtime, although I know you said that didn't work. Or do more quiet/down time before bed, maybe that would allow her to settle a little earlier. But if she goes to bed at 8, sleeps till 9 (13 hours!), and takes an hour nap during the day! Wow, that's 14 hours total. Most babies don't get that much at 15 months. I think the average is 13. A 13 hour night is incredible for most kids. And I don't think you're going to get much more than that. Maybe wake her 30 min earlier and see if you can get that 30 min back at naptime. Cause i don't think she needs more than 14 hours a day. And maybe if her night is a little shorter her nap will be a little longer. Don't know if any of this helps, but good luck.
