We sidecar'd a spare cot from a friend two weeks ago (I think my DD is about 2 -3 weeks older than yours) so DD now starts the night in her cot (restlessly, sometimes waking every sleep cycle) and then when we go to bed she comes in to our room once age wakes after we've retired for the night. Sidecar'ing had improved my sleep significantly, and there is plenty of room for DH, me and DD in the cot but still snuggled next to me, our mattresses are the exact same height with no gap. Even if DS comes in (often about 5am) we each still have space with means we all sleep comfortably without waking with sore neck or back. DD was a wonderful sleeper until about 5-6 months. I used to only feed once a night. From then until we added the sidecar cot she was feeding 2-3, sometimes more. Now she is back to 1. Definitely give it a try. I wish I'd done it earlier now!