Nic I'm going to sound like a terrible mother in saying this but after a few weeks of doing the last feed at 9ish and then Zoe still be awake and unsettled at 12 or 1, my husband made me leave her to cry one night until se put herself to sleep. It broke my heart as it took a good 30 to 40 minutes until she did but honestly ever since we haven't had a problem in getting her to sleep of a night. She just lays there quietly until she falls asleep.
We have also started to leave a radio on in the room which seems to calm her down and help her drift off as well.
I know it's probably not the best way to have handled it but it seemed to have some impact with her.