i had very similar experience. i actually was ready to wean after a year but my son was not. i ended up doing it at 17 mos also. i did a very slow transition- over several months. nursing to sleep was the last to go.
what i did was after nursing to sleep i would put him in his crib. the first time he woke up, i would not nurse him back to sleep. i would walk him, rock him, whatever it took to get him back down. i didnt let him cry alone, but he did fuss plenty. the second time he woke i would bring him to bed w me and resume nursing. (this was for me to get some sleep). after that went better, i started doing that the first two times he woke. somewhere in there, there was a switch and he started sleeping longer. i still brought him to bed w/ me in the early morning to snuggle, but eventually he didnt wake up til about 5 am.
after about a month, i started toning down nursing in the day (he was in daycare by then so it was really only the weekends) after he was down to very minimal BF, i went away for a weekend and when i came back he didn't try. (the first time he saw my boobs (naked) about a week later he tried to come up to nurse and started crying. i just told him there was no milk in there and gave him big hugs and it was alright.
(full disclosure- my son ended up back cosleeping a couple months later after we took a vacation and all slept together on the trip for a week. so if you really want to keep her out you have to make it a permanent change)
good luck.