M.F.
Does she take a nap during the day? I find that if my three year old sleeps too long during the day she has trouble sleeping all night.
When my now three year old was two she started waking up too. She would go to bed just fine and then wake screaming and crying, or she would be playing with her toys in the dark! When I would check on her she would say she was awake because she was thirsty. So...I finally just started putting her to bed with a sippie cup about a quarter to half full with water. She doesn't wet the bed either! 9 times out of ten she doesn't even drink the water though...it's like a comfort thing I guess. But it works. My husband is the same way.
There is still the occasional episode of her screaming or trying to climb into our bed but that's normal I guess. I just pick her up and carry her right back to her own bed.
We also read her and her sister a story before bed. The usual routine is potty, bath, brush teeth, put on jammies, story, hugs and kisses, cup of water, lights out. Sometimes I let them pick out a stuffed animal to sleep with too.
Hope all goes well for you!