carmen we also night weaned around 17 months.
We did the same thing. Explained that 'milky has gone nanight', that mama needs sleep. There was definately understanding there. Even though we haven't needed to say it for months now, we still here our DD whispering herself at night time 'no milky at nanight. milky sleeping'. I could tell she got it even when she didn't have the words to say so.
We co-sleep and continue to. We started with a certain window of time (no milk from bed until 3am).
What happened is that nights 1-3 were extra challenging. She understood, but was sad and frustrated with trying to fall asleep. She would try a new position, get quiet, and then if it wasn't working start to cry again. We tried all kinds of ways to comfort her. The best for us was to keep her in bed - not to rock her or put her in a sling. Sometimes she wanted cuddling, and other times wanted nothing. We would sing a bit if it helped. Often it was best for our DD to hear us a little when she woke, give some loving snuggles, and then she would want to be alone to fall back asleep - it seemed like some of our efforts kept her more awake. We would fake sleep and try to relax, even if she was crying. We'd praise her trying, and just be creative. We were all there togehter, she would crawl and snuggle into us at different times. Often she fell asleep between us, head at our feet, sprawled out :) She did cry a lot. We were okay with this at this point for our DD because we were there, comforting her. She seemed to understand. She was learning and was sleeping better. We could see her learning to fall asleep without milk faster and faster. And she was happy and normal during the days.
By the end of the week she sleeping for 4-6 hours after going to bed. she definately would wake and fall back asleep without us noticing, because she moved around alot.
We had that window of until 3am - often for the first weeks she would still wake between 1 and 3am and have a much harder time gettign back. We were REALLY flexible with each other (DP and me). If one of us needed a break, if we needed sleep, or if we thought it was too much for her we would 'fake' morning time and just feed her at any time. This means we would say "DD is it morning time?" she would cry YES! and then I would open the window curtains and fake that the sun was out and say "Yes, it is morning! It is time for milky!" (without her seeing it was still dark).
We did this at 3am each morning too. And then she was allowed to drink for the rest of the night.
As much as we could, in a healthy sane way - we kept moving the time later and later. Once she got through the 1-3am time without waking, she really had the ability to put herself back to sleep and started to sleep until 5 or 6am. We continue to say 'its morning, do you want milk?'.
anyways - from every hour to sleeping mostly until 5/6 took one month. It could be shorter or longer I think depending on how you and your DP feel in the process and how your DD is coping.
It was worth it, and we never felt like our DD was being ignored or pushed too hard. We do this process over again after illness (when we just feed on demand again) or big changes. She adjusts faster now.
oh yes. Sometimes we woudl take turns sleeping away from the family bed to get a really good sleep in the early weeks. Even if DD wasn't crying, she was moving around alot and it meant some really rough sleeps.