Nearly 12 month old suddenly won't sleep!

[Supermoo]

I hope someone here can help me figure out what's going on!

DD2 is nearly one, she's been a pretty good sleeper for months. She's still breastfed and occasionally woke once in the night for a quick feed. I always put her in her cot awake though, so no sucking dependency for sleeping. She goes to bed ( after tea, bath, story, feed) at 7pm and used to sleep from then till around 5.30-6am.

Great, I thought, got it nailed...

Until weds last week when she screamed at me for TWO HOURS before I breastfed her to sleep in desperation. This h refitted every night since, and every nap time. She has naps in her pushchair if we're out. Last night it was 10pm before she went to sleep.

I've tried:
Pick up put down
Warm bottle of milk/ snack before bed
Calpol (she just got her first teeth and is a bit unsettled at times with them)
Leaving her for increasing amounts of time (completely against my instincts, but I know some swear by it)
She has a comfort blanket
Tried lights off and with dimmed light
Tried music and light show

Nothing helps!

Please tell me it's a phase! Even better, would love some ideas how to sort it out!

is there any chance you can you cut out her daytime naps in her pushchair?

Yes, she doesn't nap as such in there, more falls asleep when we're out. She is still very tired at 7pm, which make it harder to settle her still!

Nothing very constructive to contribute I'm afraid but I'm sure it is just a phase. I've followed the Wonder Weeks theory since DS was 3 months (now 10 months) and his sleep has always been much easier during sunny spells and more difficult during cloudy spells. Their website has a chart that shows when they are. The idea is that there are set, predictable weeks when babies brains start firing off in new patterns that let them learn a new skill such as 'categories' or 'sequences' and this new ability means the world suddenly looks different and scary and makes babies cry, and be cranky and clingy (the 3 C's). DS has followed the pattern almost to the day (calculated from due date rather than birth date) and I always find his difficult times SO much easier to cope with when I feel I know what is going on in his little head, and that a sunny spell with more sleep is just around the corner!

What naps does she have? It was at this sort of age that my DD dropped from 2 naps to 1 per day and we had an awful time with her at bedtime for a few weeks until one night I put her to bed at 6.30 instead of 7pm and she went down like a dream and had a really good nights sleep. Worth a try.