I think it's great that you're still nursing your 20mo old. The WHO says until at least 2 years and beyond. Keep up the good work! Trust me, as a mom who has long-term nursed and known a lot of long-term nursers, they wean themselves. It happens naturally with both of you guiding it. As far as moving her out of your room, find out why your husband doesn't want her in there anymore. She really does not NEED her own room, that's just society's pressure on you. I know especially full time working moms find that the night time closeness helps fill in the gaps when they don't feel like they get enough together time. On the other hand, if it is putting a strain on your marriage, try to come up with a compromise, putting her to bed in your room, but moving her when you guys go to bed or something like that. Remember, just because you've never heard of it being done, that doesn't mean it hasn't. You can do anything, as long as it works for your family.
As for my story, My first started sleeping with us at about 6 months (I thought I had to have a separate room for her, because that was all I had heard of) and did until about 2 months after my second was born (she was 2.5). My second slept with us until about 20 months, and now she goes to bed in their room (it's much easier, since they get to room together, they love it), but usually ends up in our bed by morning. She still nurses much more than your daughter, which is fine by me. I've seen the weaning process happen naturally, and it is so peaceful that way. For us, it was the way to go.
Anyway, just keep in mind, do what is right for YOUR family (which includes all of you, not just your kids). Think outside the box to find what is right, and don't buy into someone who tells you that your kids must have their own rooms and you must use CIO OR someone who tells you that cosleeping is the only way. You'll find your way. It sounds like you're a great mom, trusting your instincts, and you'll figure it out. Remember, things change. Don't think if you do one thing that's how it will always be (even CIO, sometimes they get up anyway!)
K.