Thank you all for your helpful hints.
I just read sleep sense, but it doesn't have anything in there about what to do when your child gets up and cries and bangs on the door in the middle of the night. DD is really good and going to sleep now, I don't hear a peep out of her, it's just in the middle of the night where she wakes up.
DH isn't to keen on the whole night light thing as he thinks that she will become scared of the dark if we introduce it. I would love to leave the door open but once again DH won that battle. And as for music, my house has to be completly dark and quiet for DH to get to sleep, so thats a no go.
When she sleeps with me she will wake for a second, give a cry until I say "it's ok, mummy's here, go back to sleep." and she will do just that. she will do wake a few times during the night.
DH and I have decided it's best to take her to see and Dr, just in case something is wrong. her appointment is tomorrow so I will let you know how things go.