I realize by now you may have found another solution, but I’ll post this anyway. Making the crate comfortable and “their own space” is a good start but she needs to be rewarded for going in. Ours only has to see us walking towards the treats to run into his now. If we have to say, “go to bed” he’s like a cartoon character scrambling (hardwood floors) to get into his crate. He gets a treat and close the door. The first few nights he whined for a while, but after no reaction from the humans, he stopped. Now he only whines when he needs to go out, when the other dog has eaten his food or he wants to play. I’ve started leaving one of his Nylabones in the crate with him so he doesn’t get bored and chew up another bed. They are intelligent dogs but it takes time for them to get used to your routine and to learn what you expect.