Does she nurse for about the same length of time? When she starts looking a little bit drowsy, I would unlatch her, cuddle her for a few, and then go ahead and lay her down- chances are when she starts almost falling asleep she isn't getting much milk anyway so she won't miss any food if you unlatch her when she is in the phase.
My kids have always been pretty good sleepers, but when they would wake at night and I knew they just wanted to nurse to sleep, I would go and pick them up, cuddle them a little, then put them back in bed and let them fuss. I usually tried to give them tools to self soothe- if they were older maybe a bottle of water or a special blanket- maybe a toy they like to play with. I was always worried they would wake my other kids too, but in the end I figured it was better to have them both up for a few weeks of getting the second one to sleep through the night then it was for months and months of waking up to cater to just wanting a little soothing. Obviously, letting them cry for hours on end isn't good- so I give them a little time, go pick them up and cuddle then put them back down to sleep- even if they fuss again you give them security knowing you will come back if something is really wrong, but it is time to sleep. I know this is a hard spot to be in!
I'm in the same boat. My daighter is 8 months. I did "break the habit" but it all went down the drain when she got sick and I brought her in bed with me to keep an eye on her. I did it by nursing my daughter 30-60 minutes before her bedtime with the lights on and door open so she wouldn't think it was bed time. Then when it was time to go to sleep I held her for a bit until she was sleepy, then put her down. She cried bloody murder. I stood by her crib and comforted her. Took a hour and a half the first day, forty-five minutes the next, and then 20 minutes. By the 4th day I could put her down and she would self soothe to sleep. It was VERY hard and stressful. It's been about 2 months since I've been nursing her to sleep again. I just dread going through that again. Nursing your baby to sleep is only a problem if it's a problem for you.