N.S.
When our son was moved to a big kid bed at 3 1/2, he had some of the same issues. I know it's just a phase and they are supposed to grow out of it, but I'm not one to sit around and wait for the growing to happen. I wanted my sleep too! We attacked the problem 2 ways at once:
1. Preventing the wake up at night: We created a "talisman" of sorts to ward off bad dreams, etc. I bought a plaster Spiderman and he painted it and put glitter on it and we hung it on his wall right by his door (about 3 feet off the ground so he can touch it and see it all the time). He believes that Spiderman won't let anyone or anything bad happen to him while he's sleeping. If your daughter is into princesses, I heard that Ariel is a pretty tough cookie. We also told him that any scary things out there are REALLY afraid of Mommy. And since Mommy is in the house, they won't come any where near it. He believed that one, big time.
2. Rewarding sleeping all night. We kept a sticker chart for 2 weeks. He had to "sleep all night long" to get a sticker. Once he got 10 stickers out of the 14 nights, he got to go to the store and pick out his own hot wheels monster truck. He had seen it at the grocery and we "visited" it each time we went, but he couldn't bring it home until he got his stickers. We did this 2 times and it worked like a charm. We also reminded him each night as we were leaving his room that we loved him and would like him to sleep all night long so he could get a sticker and pick out that monster truck.
Good luck!
N.