Thank you so much for your replies.
Her WU time is all over the place at the moment.
After I wrote the previous message, DD went to bed at 6 and slept until 5.45, had a feed and went back to bed until 8! Obviously, writing here sorts her out!
She has all her front teeth (got her first at 4 months!) I think her molars might be jangling a little but normally paracetamol sorts it but not this week, which leads me to think its not that.
So, I should work on keeping the morning nap as the long one but just work on pushing it out? Early bedtime until it's all sorted? How long do transitions normally take?
Thanks again for your advice