I found instituting regular hours was an effective way of getting my ds to sleep. It works for adults too! I did this at 8months so it was easier, I think. We were very firm. Bedtime was always the same routine, tea, bath, play and storytime, bed. My ds stopped wanting a night feed at around this time anyway.
In your case, I think you should maybe stop thinking it necessary to feed her to sleep at this age - your dd is maybe growing out of this naturally. And by insisting on it, you might actually be keeping her up and awake. Instead, you could feed her as normal, but when she starts to get wriggly, stop, maybe sit with a book and read a story then tell her it's time for lovely bed - I talk a lot to my son, keeping up a murmured stream of chat - 'oh, it's lovely bedtime now, sleepytime, time to go to sleep, that's it, into the cot, and into your sleeping bag, all cosy blah blah blah' then I kiss his three toys as few times, stroke his hair and kiss him and then leave. It think it's possibly that if she is pottering around, she is interested in the world asking for some winding down time by herself, so maybe instead of just feeding you need to give her some book time. I also find that if my son starts to fidget, wriggle and get off my lap it's an absolutely 100% sign that he is tired and needs to sleep. I can keep him up but it's not in his interest at all. So I keep an eye on the clock and he is always in bed between 7pm and 7.30pm. Have you tried giving her lots of cuddles and then putting her in her cot awake with her toys, talking reassuringly to her, stroking her hair etc, and then leaving her to it? She might not cry at all or just cry very briefly. My ds often cries just as I leave, but is almost invariably asleep before I am halfway down the stairs. I think his cry is a mild protest, not a sign of anguish or anything. More 'just a minute mum!' than existential angst. I suppose what I'm trying to say is, follow her cues if she not longer feeds to sleep, try a change without expecting it to involve lots of crying and maybe allow a couple of cries as it seems to me that this is how some babies either wind down or make their last half-hearted protest before they get their sleep. BTW, my ds slept through without any nightime milk from 8months.