Well, we have had a fairly bad day with lots of crying and misery - DD had immunizations yesterday so I think she was feeling very uncomfortable.
We did have some naps but again she seemed to snap awake at 30-40 minutes into her nap, and can't seem to be resettled. She seems tired when she wakes up so rather than being done with her sleep I think she is struggling to get through a sleep cycle.
We have also started a bedtime routine tonight - play, bath, massage, book, feed, bed. Which worked a treat.
Thanks for all of the tips everyone!