A big strong
to swaddling. Seriously, it saved our sleeping for the first six months. We had to download youtube videos to learn how to swaddle properly.
You should have seen us practicing with the blanket and the baby, huddled in front of the computer!!! Seriously, a swaddle will help a LOT. Just don't worry if it seems too tight at first, or if she screams bloody murder while you're getting her into it. Wait about 2 minutes and she'll likely calm right down and love it... and you'll be able to get her in and out of the co-sleeper without as much trouble.
Also, if you have something that smells like you, like a t-shirt you slept in the night before, you can lay the baby on top of that and the smell might soothe her.