well i was ust going to post somehting similar as I think my DS is going to drop a sleep soon
Heis 1 yr old now and normally sleeps 9 to 11-12ish and then 3 to 4-5 ish
last week he has been not going to AM sleep just sleeping after lunch which is fine on the days she has AM nap I am finding it hard to put him down in the PM as beig awake from 12-7.30 is too much for him.

I usually put him into cot with his teddy that plays music and leave the room. I try and kee activity to minimun just before I try and put him down.
I would suggest making a routine, like reading a book or sitting having a cuddle for couple mins before trying to put bubs to sleep
Does bub fall asleep on her own at night?