IM, have you thought about putting her into a bed, with a special 'big girls quilt' that she can choose herself?
Tell her for the next week or so 'It's nearly time for you to have big girl bird, I can't believe it! I'm so excited' and really build her up. Give her the Argos book to pour over looking at beds and quilts and sheets, read books about bedtime being a magical time.
Once she is mentally prepared for it, make the change, do it when she isn't too tired so not likely to get tetchy, get her to help you make the bed up, and totally overact how comfy it is, get into it 'wow! I might have this bed myself and you can sleep with Daddy, at least I won't have to hear his snoring!!' big and faces.
Read a story and generally spend quiet time in and around her bed. Then on the first night (new pjs/nightie also help) when you put her in the bed, (and act really excited) hopefully she won't kick off too much, if she does then start rapid return.
Just pick her up every time and take her to bed, 'It's bedtime sweetheart, you need to go back in your bed' say it softly, don't make it seem like you are telling her off, continue this until she is asleep. Not saying anything more than that one line, do not enter into conversation and try to avoid eye contact after that sentence.