D.,
I have 4 children and have done this transition several times. Here is my take: We transitioned my firstborn to a bed when he was a little over 2 years old. His sister arrived when he was 21 months old and it was time to move her from the bassinet to the crib. It as tough, he fought us in many of the same ways your daughter is. We ended up getting into terrible habits of coming to him multiple times before he would fall asleep, back patting, singing, all kinds of habits that were thought to break and made bedtime long and exhausting. In the end we put a gate up in the doorway of his room so he could not get out. He would sit at it and scream. We did all this because we thought "it was time" for him to move to a big boy bed. My 2nd child was nearly 3 when she transitioned to the bed. It was a piece of cake, she was ready, willing and made the transition easily. As did every child after that. In fact my 4th child decided on her own one day that she wanted to sleep in her sister's bed with her. I thought it was just for fun, it ended up being the end of her sleeping in the crib. She moved when she was ready.
I think the first child is always tough for these new transitions but I also found that if I let my children decide when they were ready to make the transition to a big bed it was surprisingly easy and painless. I also think children 3 and older make the transition easier (at least that has been my experience) It sounds like you are not yet pregnant, which means you have at last 10 months if not more before your new baby will need the crib. I would give your daughter some more time, try again in a couple of months, talk about it with her, play up to "big girl" aspect. I think you will find it to be a much easier transition and you will still have plenty of time to work out the kinks and for her to "detach" from her crib before baby number 2 arrives! Good luck