"I have a 17-month-old daughter that sleeps with me. I weaned her from breastfeeding at 12 months, but I am having trouble transferring her from my bed to her crib. My husband has been sleeping on the couch for the past year and a half and is tired of it. I too want him to come back to bed. I'm also 8 months pregnant and I would like her to be in her crib before the new baby comes, (the new baby will not sleep in bed with me, I've learned my lesson.) Is one month enough time to transfer her? How do I go about it? I've been told to let her cry herself to sleep but this hasn't worked. After four hours of her screaming, crying, pulling out her own hair, trying to get out of the crib, and her throwing herself against the inside of the crib, I give up, and let her back in my bed. What should I do? I don't want her to feel rejected, especially with another baby coming, but I really want her in her own bed. Please help."
First of all, please please don't feel like you "learned your lesson" and can't sleep with your new baby. You'd be doing yourself a huge disservice by giving up the ease of cosleeping with a newborn just because you don't want to be cosleeping with a toddler a second time. Think about how rough it's going to be trying to comfort a 2-week-old in a crib while also dealing with your older child's sleeping stuff--you'll have a much easier time if you cosleep with the little one for at least a few weeks.
Many many kids have a window right around 6 months in which they stop cosleeping well and do better in a different room than their parents. Those of you who have kids older than 6 months are probably nodding your heads right now, remembering when the extra wakings and kicks in the kidneys started right around that time. Those of you who switched your kids out of your room right around then are also probably remembering how it was way easier than you thought it would be to make the switch. I feel like there's another window of time right after the 9-month regression is over (around 11-12 months) when you can make the switch relatively easily.
I think for a lot of us the first time around we feel like cosleeping for as long as possible is going to be the magic bullet that makes our kids happy, and if we quit cosleeping things will all go into the crapper somehow. So some of us miss that first window because we just don't want the snuggling to end, even if it becomes more work than sleep. There's nothing wrong with that, and it's normal. Heck, some of us miss the window with a second or third child for the same reasons. Just know that if you don't want to be sleeping with your second baby this long you can still start out with the baby in your bed and have a relatively easy switch at a couple months or 6 months or 11 months.
But back to the immediate problem. The good news is you don't have to worry about nightweaning. The bad news is that you've only got a month and your daughter is at one of those clingy times. (If only your baby could stay in until your daughter was 20 months, I think you'd have an easier time with the switch.)
But you can have her in her crib for at least part of the night by the time the baby comes (assuming you don't have the baby too early), and I don't think it's going to be a Battle Royale. The last thing you need at this age is to set up a situation in which it's a battle of wills over who controls the sleeping situation. It's just not going to end well, and frankly, the toddler will probably win. (Also, anyone who tells you seriously to let your child cry for four hours is not your friend. This is unreasonable emotional abuse for both of you--a pregnant lady doesn't need that kind of stress--and is just going to cause more drama around nighttime and completely backfire. So stop listening to parenting tips from that person.)
The first thing I think you should do is reevaluate her sleeping situation. You don't want her to feel like the crib is her punishment. You want her to think it's fun and cool and for Big Girls. It may be as simple as getting Dora sheets or putting Bob the Builder stickers all over the crib. Or, she may be the kind of kid who pushes back really hard against a crib but is so proud to be in a toddler bed that she stays in it all night. You know what her personality is, so think about what's going to motivate her most. It doesn't matter if this is a true long-term solution for sleeping for her, since everything's going to be different with her sleep when she hits 20-21 months anyway. So if you need some crazy cool thing to get her sleeping in her own bed initially, just go with it. My older son is absolutely in love with his racecar bed. I have a friend who had her daughter sleeping on a child-size Aerobed at that age, and her daughter loved it so much she'd stay in it all night (and she'd been climbing out of her crib for weeks before that). I know another mom who put her son's most annoying talking toy in his crib and that was the only place he was allowed to play with it, so every night he'd fall asleep listening to that toy happily (and sometimes she'd hear him listening to it in the middle of the night, but she didn't care because he stopped calling for her). If she were a dog I'd suggest putting a juicy bone in her crib, but you get the idea. Whatever is going to make her want to be there is what you should try.
Next, you're going to harness her increasing verbal and reasoning skills. This is such a tricky age because they really can hardly say all that much, but their receptive verbal skills are huge. So they understand so much more of what you say than they can tell you, which makes you think they don't understand that much. But if you work on a certain concept she'll get it. So start hyping the Big Girl Bed, with the idea that Friday is going to be an important day because she's soooo big now that she gets to sleep in her own Big Girl Bed. And keep hyping it for the rest of the week as if it's going to be a ton of fun, and that she's only allowed to do it because she's such a Big Girl now. She's not going to be able to tell you that she understands, but if you have a few days and you talk about it a few times each day (and remind her before bedtime every night about how it's only a couple more days until she gets to be a Birl Girl!), she'll get it. And don't mention the S word (sister, big) because you don't want to link the baby with the Big Girl Bed.
The last thing, which is key, is that your husband is going to have to be responsible for the heavy lifting part of the bed switch (which is why I said she'd start on Friday, assuming your husband will be off work on the weekend--if he's not, the make the start date the night before he has off work). You can put her to bed in the crib for the night (with whatever toy or cookies you need to get her excited to be in there), but then he's got to be responsible for wake-ups. The idea is that if she doesn't have the same situation to go back to (in bed with you) then resisting the crib won't be as satisfying because she won't really get what she wants anyway. If waking up only results in Daddy coming in and retucking her or rocking her (or bringing her in to bed with him) then there's no real incentive to wake up. She can't go back, so she might as well go forward.
It sounds like your husband hasn't been responsible for a lot of the nighttime parenting so far, but that's going to have to change when the new baby comes (it turns into a man-to-man defense, which he'll probably understand instinctively). So he might as well ease into it now, and get his spot in the bed back at the same time. It's to his advantage on so many levels to do the switch, but go easy on him by starting on a night when he doesn't have to work the next day.
I'm guessing that this plan will get your daughter into her own bed for at least part of the night (which will gradually stretch longer and longer over the month, we hope), but if you do it for 3-4 nights in a row and have no success whatsoever, let me know and we'll figure out what to do at Defcon 5.