My 16 month dd has started waking during the night. She's previously slept through most nights since she was around 7months, she does occasionally wake but will resettle within 10 mins. However the last few weeks she has been waking 2-3 times and been wide awake, wanting to chat & play! Last night she went to bed at 7 as usual, woke at 11.30, took an hour to go back to sleep, then again at 2, & 4 too.
How can I stop her?