linniewith2, I havwe just had the same thing with my dd1 (aged 2 and a bit) who co-slept, I have a dd2 who was about 8 weeks at the time. I used a technique called gradual withdrawl. First, I found moving dd to a bed a big help - get dd1 to help to choose bedlinen etc. If you are worried about her falling out, you can put the mattress directly on the floor. We also have a stairgate rather than a door but if you do that you have to make sure there is nothing in the room that can be used to climb on to get over the gate. We also have a plastic photo holder with loads of pics of dd1 enjoying herself hung where she can see it from the bed, and she has a special bear that she 'looks after' for mummy.
We have found a regular bedtime/routine a must. At first I had to sit there feeding and reading stories at the same time, but now dd2 is older and can last between feeds, sometimes I leave her in her cot and sometimes she sits in her chair and listens to the story!
To do g.w., start by sitting beside your dd1 as she falls asleep, either on her bed or in a chair if she is in her cot. Leave when she goes to sleep and repeat every time she wakes, naps etc. Then gradually move further away - the end of the bed, then a chair beside the bed, then move the chair towards the door until you are outside it. Remember to be really boring. You have to do this every time - I sat one night on dd1's bed, b/feeding dd2 and picking out my desert island discs in my head for two hours! The point is, this does work - in two weeks we had dd1 going through the night and now we have her bedtime routine, story, lights out, prayers, relaxing c.d. on and I leave her to it.
As for dd2, I am currently keeping her up until I go to bed. She goes through the night (!) and when I put her to bed at the same time as dd1, she started night wakings again, so at the moment she naps in her travel cot in our sitting room in the evening if need be. I do have a set routine that I follow with her at bedtime so that she knows what happens - bath, massage, feed, bed. I think that the regular bedtimes will come once she is weaning.
I have to say that dd1 has showed no jealously of dd2, but then I found that including dd2 in her routine has helped her to accept her i.e. they can do things together. Also we keep making a point of how much dd2 loves dd1 - 'oh, look, she's smiling at you, she really likes you' etc seems to have helped.