C.M.
Can't really help her more than you already are. If you are still nursing on demand and/or at night, she's going to keep waking up. Do you use a binky? If so, try that when/if she fusses. My kids were 2.5 and 6 months when I moved my son into the room with my daughter and for the most part, she didn't wake up when he cried. I'd put a fan in there or sound machine to block out noise if you do not already have one. Also, to get more sleep yourself, I recommend either nuring in a rocking chair in their room (so you can quickly put the baby back to bed) or laying down in your room (so you can close your eyes!).
Good luck!