Some advice would be greatly appreciated. My dd is almost 18 months and has had a rough month. Several bouts of illness, teething (6 teeth), diapers that leak

have caused her to wake at night. It seems it has become a habit now. The wake time varies each night, but she wakes calling for "Mumma". I wait a minute or so as it begins as a "mantra" cry, but it always escalates and she is standing up in her crib calling out. I go in and lay her back down. I usually don't say anything. She tends to jolt herself at 20 minutes and again at 45 minutes. I'll go in again when she yells out (ie. at the 20 and 45 minute mark)...at these times I'll usually say in a firm tone, "It's time for sleep). Usually after the 45 minute mark she'll fall asleep (or we'll start all over again)

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My dilemma is that she has always been an independent sleeper, and I don't want to stay in her room as she is falling asleep during these night wakings. I've thought about setting my alarm to go in and stir her before she wakes, hoping to set her back into a sleep cycle, but she wakes at different times every night. She has no problem with her afternoon nap which is 1.5 hours.
Oh...also she only sleeps on her back (she has never rolled over in her crib). I sometimes wonder if she wakes because she is uncomfortable. She also has never taken a soother or sucked her thumb(with my ds we just had to plug his soother back in and added a spare in his crib in case he lost it) Any strategies or advice would be greatly appreciated

Thanks!
Janine