Hi there,
Hope you have now got your little one asleep?
Has anything changed in the last few weeks which may be upsetting up her? New house/baby/nursery etc?
I have previously used the 'supernanny' 'stay in bed technique'. Basically you do your normal bedtime routine then if she gets out of bed the first time you remind her it's bed time, take her back to bed, kisss cuddle and leave the room.
Second time, do the same but with a firmer voice and make the cuddle brief (I try to avoid eye contact).
The 3rd/4th/5th etc time, you say nothing, tuck her in and leave the room.
If you decide to do this, she won't give up, but trust me it will work. You have to remain patient and just keep repeating step 3 over and over. She will go to sleep eventually. It is horrible listening to them cry and you will feel awful, but try to stay calm. depending how stubborn your little girl is this may take about half an hour to work, but it will get shorter each day you repeat this process, until she will just accept it is bed time.
I am on DC 4 now, just had to do this with my 3 year, she used to go to sleep fine but started playing up when her new brother appeared. Took me 3 nights for her to get back into her routine. The first night was the worst, she would call out 'Mummy, Mummy, kiss Mummy'. But I just had to walk out and not answer her.
If you don't fancy that suggestion how about star/reward chart. is there something she would really like? Have a look in the argos catalogue, get her to choose something she would like but explain to her that she only gets it after getting 7 stars? 1 for each night she goes to sleep by herself? Would she understand this yet, my daughter has just turned 3 and doesn't understand the concept of reward charts yet, but your daughter might.
Sorry for long post, but I have gone through this with all my children, it will get better. You and your DH have to back each other up. So if you are putting her back to bed make sure he doesn't come in and start cuddling her and vice versa, as it will undo all the work.
Let us know how you get on, good luck