First of all Carolyn my apologies for taking so long to answer your post. THe site's been cooky lately and it appears to be down when i happen to log in.
I am hesitant to about what to advice. My standard advice would be go cold turkey and move her to her room TONIGHT. Maybe you can plan ahead for a couple of days telling her how exciting it will be to sleep in her room again and how she has to teach little bro to sleep in his own room, and she has to play big sister role, etc. Then you could buy an special item for her room, like a new pillow, new sheets, a new teddy bear/dolly that will go to sleep with her. The idea is to make an excitement ocassion out of the moving. She's old enough to understand the trade and the reasons so you have to talk to her about this a lot and continuosly to make her get in tune with the plan. She can even choose if she'll nap in her own room or at mommies (she might want to stay at mommies for naps for a while but since you say you don't mind i think this can make a good compromise).
Then is the whole changing environment playing a role (The vacation, the birth and then your sudden disappearance because of high blood pressure). I'm sure it was pretty traumatic on her and I'm sure you did the right thing too by letting her in your bed while the turmoil lasted. As Im sure it has happened plenty of time to recover from the original shock and start looking for things being the same as they were. She had reassurance and now things are "normal" again, it's time to move on. She's now used to her little brother's presence in house and in another couple of months she won't even remember life without him so I'm sure the newness is over. Besides, since you're thinking to move lil bro to his room soon, you can make her "help" you do that by showing him. I'm sure she'll be thrilled with it and most willing to cooperate. THen you can say out loud in front of everyone how helpful she was by showing Lil bro how to sleep on his own room.
Although some resistance is to be expected, I'm sure you can deal with it as long as you prepare yourself for a week of struggle. That means that either dad/grandma are on board for a few rough nights where you'll have to be doing either walk in/ walk out or gradual withdrawal or toddler pd (depending on her temperament and whatever you think suits you best, the methods are described in the FAQ's section at the top of this forum under the TItle Teaching Independent Sleep). I don't think it will take you longer than a week since she's old enough to understand and more over, since you've been reassuring towards her when things had gotten rough so she knows mommy will be there for her when she needs it and shouldn't take this process anxiously. However, this kiddos can surprise us and come up with weird reactions. DOn't worry about it, we'll be here for you during this process, whatever you choose and decide. Keep us posted on your progress.
