Hell A.,
I have a 15 month old girl and I'm 9 weeks pregnant with baby two. My daughter sleeps through the night. We tried many things to get her to sleep in her crib so maybe some of our ideas might help you. First though, maybe she's not ready for a big bed? My daughter is still in her crib and I'll probably keep her in it for quite some time. With that said, here is what we've tried...
Make sure her tummy is full when she goes to bed (give her a sippy cup of milk or a snack before the bedtime routine). It's possible that she is having a growth spurt and she's just a little hungry. Also make sure she's not too hot/cold.
Also, is she taking a nap/naps during the day? Sleep begets sleep. I've noticed with my daughter that she'll sleep better at night if she's had a good nap during the day.
Tonight when she wakes up, have your husband go in her room and pat her back to sleep. Every time she tries to stand up have him lay her back down (even if she tries to stand 100 times). Have him leave the lights off and not interact with her. He'll just want to keep laying her back down and patting her bottom. She'll eventually get tired of resisting and fall back asleep. He may have to do this for a few nights but don't give in and don't get her out of her bed/crib.
Have you ever let her cry herself back to sleep? Every now and then my daughter will cry in the middle of the night but we wait about 5 minutes to see if she's actually awake or just dreaming. Almost everytime she'll fall right back asleep.
Your daughter is probably in the habit of someone coming in right away to save her. Maybe you go in too fast and you end up waking her up even more? I would try patting her back to sleep for a couple nights and then just let her cry it out and see what happens. She'll eventually feel comfortable falling back asleep on her own without you or your husband.
I know this sounds harsh but it was recommended to me and it worked. My daughter never cries herself to sleep anymore but when I was first transitioning her to her crib and overnight sleeping she certainly would cry. It only lasted a few days but she's been enjoying long nights of sleep ever since and so have we.
Let me know how things go.
God bless,
K.