Hi Fedup - my DS is 4.5 months so just a bit younger than yours - I don't know if this helps but I always I'm always interested in what other people with babies the same age are doing!
DS gets a BF at about 5ish, then a full 8oz bottle at 6.30ish, down for bed by 7ish. He is in a cot in his own room, goes to bed in a merino-lined sleeping bag (temp in his room in the evening is about 19/20 degrees) with dummy, muslin & white noise.
I change his nappy at 10pm (dark room, minimum talk etc), adding in a nappy booster terry cloth (he is a champion wee-er and if I don't do this he leaks right through) and dreamfeed him. This seems to take him regularly to 4 - 4.30am, I change him again as the nappy is sodden & feed him. Then he wakes at 6.45 - 7amish.
He was definitely more unsettled round the 4 month mark, we had about 2 weeks of him waking several times a night. Bloody shattering. I'd just shush, put dummy back in and leave him to re-settle. Occasionally I would feed him at 1am and then again at 4am, just to get some peace. He has found his thumb though and seems to prefer it.
I'm going to start him on solids this week, he's a big baby (about 20lbs) and it will be good to start lessening the liquids in favour of calories from solids, from a nappy leakage point of view at least!
Would you consider putting her in her own room? Both of our sleep improved a lot when I put DS in own room, before that I was hopping up every time he stirred and popping him on the boob. Now he has more of an opportunity to stir & then put himself back to sleep before I rush in & wake him up!