Hi K. -
I also have a 7 month old. He slept well through the night from 2 mo. But then at the beginning of 6 mo. he started waking up crying. We would go in and get him, give him a bottle and he would fall back to sleep.
This is my 2nd child and I remember the 1st one had periods of sleeping well for me then reverting back. Also both boys have Acid Reflux. So we had to be sure that they were elevated for a bit after a meal and at some points for the older one, we elevated his crib.
Are you putting her to bed awake or asleep?
1. Maybe try putting your daughter to bed a little later than you are & with a full stomach?
2. We also have a CD player in both of our boys room, with one CD in it (Kenny Loggins, Return to Pooh Corner). Whenever we put them down to sleep, we turn on the CD which plays softly in the background. If I need to go in to either of the kids in the middle of the night, I turn their music back on. Supposedly this will sub-conciously trigger them to go back to sleep.
3. Other things for a good night sleep: cool room, and some kind of 'white noise' like a fan(not directed right at her) or cool mist humidifier - which I see you tried already.
4. Routine, we always have the same bedtime routine, everynight. There is a period of calming down, snuggling with a few books, putting on PJ's, bottle, quiet, music, sleep.
I also do let my 7 mo. old cry it out, but I can tell when its his cry it out for a few minutes & he'll fall asleep or if it is his rage cry, then I go get him.
In the end, just venting is good. Because, based on my 1st boy, I can tell you that this happens from time to time.
I remember he was such a good sleeper then one day(15 mos. probably) he just wouldn't go to sleep. We were up all night for several weeks. I took him to the Dr. and he was checked and the Dr. said that the baby was fine, that the baby could control two things, his eating and his sleeping. And that the baby was trying to exert some control over his bed time. The Dr. said that we should let him cry it out. The first night he went to bed after three hours of crying (we checked on him periodically) the next an hour and a half, the third night 45 minutes. Then finally, he went to bed.
Good Luck, email back if you need anything.
W.