Have you used the controlled crying technique before? I used it successfully with both of my children. Sometimes I had to revisit using it with my daughter if her sleeping was disrupted by things like travel. Never use it if your little one is not well - its only if she's waking out of bad habit (which it sounds like she is!)
Method:
Let her cry for five minutes.
Then go in and say shuussh, its time for sleeping, - place a hand on her if you like (or even a cuddle) but no interaction only to say its time to sleep, no eye contact and no negotiating with her, just be calm, almost robot like, and keep repeating that its sleepy time. Once she's calmed down, leave.
Leave her for ten minutes, then go in again. This time just place a hand on her. No talking. Then when she's calmed down, leave.
Let her cry for twenty minutes, go in again.
Repeat this method doubling the time each time. This way, she learns that you are still there (she's not feeling abandoned) but she's also learning that she's not getting anything out of crying and will eventually give up and go back to sleep.
The key to this method is CONSISTENCY. So if you choose to undertake it, you must see it through and not go back. You need to be quite strong mentally and focus on the outcome. You also need to allow some time. Sometimes children will respond to this method within a couple of nights, others need longer. This method is not for everyone - crying can be hard to take but I liked it as my children responded very quickly to it and because of the idea that they knew that I was there so you are not just 'leaving them to cry' - hence the name controlled crying. I found it a reassuring way to teach my children to sleep and they are now both good sleepers. As I say sometimes I've had to revisit it with my daughter if she gets out of kilter but thats because of changes we have made to her sleeping habits, not her. And please I must say again this method is not to be used when children are teething or ill! Hope this is of help - good luck in whatever you decide