Day 114: Why won't she go to sleep?

Despite all the sleep problems Mari has had, going to sleep at night has seldom been one of them. Going to sleep for naps, yes. Waking up at night, yes. But she has seldom had trouble falling asleep at night, since she's tired then. Now, all of a sudden it's a huge problem. She still seems as tired as ever. She's still napping at more or less her usual times, though she woke up after only 40 minutes this morning and wouldn't go back down. We haven't changed the bedtime routine or her bedtime. So why is she spending so much time getting upset before she finally falls asleep? I'm mystified.

I do definitely think we're in a sleep regression. We're close to the 37-week "Wonder Week" so that may be part of it. I don't know if she's teething -- I can never tell. I'm afraid I haven't figured out a consistent strategy yet -- I'm alternating periods of letting her cry for 5-10 minutes with going in and soothing her, but she doesn't seem very soothed by anything I do. I'm at wit's end.

I know Mari's overtired and what she needs is more sleep. But I don't know how to get her more sleep. She won't go down for naps if she's not tired enough, and she keeps waking up before she should, both in the morning and from naps. How do I stop the cycle?