Aimz, she doesn't know that she's past the magical 12 mth mark and she isn't 'supposed' to need Mummy's milk as much.

It's just a phase and I wouldn't be worried about getting her out of it unless it's really bothering you or interfering with your wellbeing. My DD went from being a beautiful settled night-time sleeper until about 14 mths when she became more like a new baby again! (It passed!) If you are finding it's too disruptive you could introduce a sippy cup of water overnight, but TBH I'd be reluctant to do it while she's still so little. It could be that she's genuinely needing the nutrition from bm.

What are her eating and bfing habits like during the day? An alternative is to fit in an extra bf in the late afternoon, early evening and make sure she's getting enough to eat. That way she might not be as wakeful at night.