How do you get her to sleep?
Are you doing the floppy arm test before you try to leave?
IME it is possible to get them from cosleeping to sleeping in their own bed without doing something like controlled crying, but it did take a lot of hanging around and feeding to sleep and 78927923 attempts to put down on my end. But the most important thing was to stick to what I had decided, because basically, when they wake up and they are expecting you to bring them into your bed, they will cry for you to do that because that is what they always have done.
When you can successfully resettle them in their bed, whether that is with camping out, or CC, or PUPD, or ssh-pat, or feeding them to sleep then lowering them into bed fully asleep or whatever, they will at first wake up at the end of their next sleep cycle, and their immediate response will be to cry for you because they expect you to come and take them into your bed.
But the more times you keep resettling them in their own bed, they get used to that and it becomes easier to do it successfully too. It's really crucial to keep building in these experiences, because after a while what you'll find is that they start to wake up and rather than go "I need Mummy" they just turn over and go back to sleep, because they are used to being in their own bed for more of the night, so it feels familiar and normal to them. In fact after a while, DS3 started to ask "Mummy Daddy bed?" and I would say "No, in your own bed" and he would basically go sod the boobs then, point to be put down in bed, and ask for his blanket to be drawn all the way up to his chin and then he would just go back to sleep 
I am a total wimp who gives up on everything, so I had to sort of train myself, in that at first I set a goal of keeping them in their own room until 1am and then I slowly brought this later over time - this worked more slowly, but it did still work, I think it was the repetition of the resettling in their bed and also me learning that it was possible for me to soothe them without bringing them into my bed. If you are less of a pushover than me, you can probably do it much quicker.
With the older two kids I waited until they were over 2 to do this because I was waiting for some mystical sign that they were "ready" but I did it at 16 months with DS3 and it worked exactly the same. Perhaps a little slower because I happened to overlap it with starting nursery.