When we transitioned A to a big girl bed, it was because we decided it was time. (It was after she turned 3.) I feel like she probably would've stayed in the crib forever, because that's just what she was supposed to do.
V, however, busted out of her crib last night when Damon was trying to put her down, and then a bunch of times in the night.
Now WTF do I do? For the BTDTs with this scenario... does this mean it's time for a big girl bed? How did you teach your kiddo to stay in it?
Also, I've been thinking about getting them bunkbeds... neither one is so keen on sleeping in a room by herself. Are they too young? Will I regret it?
We just transitioned Tristen to a toddler bed for the same reason. We do, however, have a tall babygate at their door so he can't exit the room. I figured if Trsiten could break out of the crib, he could break out of the crib tents, so we just went to the bed. It took a night or two for him to stop playing and start sleeping, but he has it now. (note- I would have totally skippedthe toddler bed with Tristen but we already had it from Koda and don't have the room for a second twin bed in their room right now).
As for bunk beds, we are going to do them next year. Mostly, I don't trust my two little daredevils from playing superman off the top bunk. Sonya has bunk beds though!
I have not reached this point yet, but many of my friends have.
I think they are ready for a toddler bed if they are climbing out of crib. I would worry she would fall at night trying to climb out.
I would get a toddler bed for now and then maybe after a year of sleeping in that then you could get the bunk beds. A would be another year older and more ready.
My cousin just got bunk beds for her boys. The one is 5 and he will not sleep on top. Are you talking about getting each a set of bunk beds or sharing a bunk bed?
I have Josie and Charlie in bunk beds. It has been a super smooth transition for us and both kids are thrilled.
That said, Josie is not adventureous and has NEVER even thought of climbing up to the top bunk. Ever.
I would be more hesitant if she was likely to climb during the night.
If they want to sleep together, maybe a double bed?
I do have a gate on their room at bedtime. Charlie can climb over it and Josie couldn't.
Our bunk bed has a rail all the way around on the top so I'm comfortable with Charlie up there. He is also not daredevily so he just goes up at bed time, lays down and goes to sleep and he yells if he needs to go to the bathroom during the night.
A lot to think about. For us, it has been perfect.
It's definitely time to move her out of the crib, just for safety's sake.
I have no advice on bunk beds though. SG went to straight from a crib to a regular twin sized bed when we moved, in the same room as Presley, and has done fine. We have one side against the wall and one of those rails Supa had on hers for the other side.
We put our youngest in a 'big boy bed' a few months ago, a few months after he turned 2. He had crawled out of the crib maybe only once, but he would 'threaten' us by straddling the rail and cry until we got him out.
We have had a wooden bunk bed set for at least a year. Gavin (4 y/o) has always slept on the bottom, and had strict orders to stay off the top, however, BOTH boys (even my youngest) figured out how to climb to the top *without* a ladder. I would catch them playing with the ceiling fan. Scared me to death.
We separated the bunks, and now they each sleep in one. It will be many years before we are putting them together again. The only reason we went with bunks in the first place is because they will always share a room, and the room is very small.
It's really nice because the top bunk is actually lower to the ground and has built in rails around it, so Tanner sleeps in that one. He sleeps really well and has tons of room to spread out. I can only imagine how much more comfortable a good mattress is as compared to the crappy crib mattress was. (He still tries to sleep in our bed everynight, but that's just a bad habit we let him start when he was a baby)
Oh, one more thing. If you go that route, be sure to check the gaps around all the rails. Ours is fairly "gappy" but since Tanner is over age 2, I'm not that concerned. However, with a smaller/younger child, I would worry about them getting stuck in the middle of the night.
I would move her to a bed. If you are unsure what you want to do you could always put either the crib mattress or a regular mattress on the floor and try it out. You could even do that with a double mattress and see how it goes with letting the two of them sleep together. Blow up mattresses can also help you test it out.
I don't know what the room constraints are, but another option for them might be a trundle bed.
Scared me to death. 
