Could she possibly be having night terrors??
Hi! I think a few things might be going on. First, she is getting to the age where she is starting to realize that she's alone at night. It's a great start that she slept through the night since one, but if you don't take care of this RIGHT NOW, it will go on for YEARS, I promise!
First, make up your mind if you want to allow her to sleep in the big bed, whatever that means, or if you still feel she needs to be in the crib. I believe you have to allow her to cry. Go in periodically and reassure her, but DO NOT pick her up. Tell her it's bedtime and goodnight and leave again. You have to create a ritual for bedtime. Bath, book, kisses and hugs, love you, goodnight, turn light out, close door. Try a night light at least. If she gets out of bed, put her right back. Don't say anything to her, just good night when you put her in bed. Continue to do this, until she falls asleep. The first few times are HARD. Breaks your heart. But it's best for her for the long run! Consistency is key!
Best of luck, I know it must be exhausting!