Sleep issues are SO hard and will make you lose your mind quick! There's a good reason sleep deprivation is used as torture.
Have you talked to the pediatrician about it? Is she teething maybe? Ear infection? I'm sure you guys have tried all the tricks. With my oldest we had to completely black out the room, have absolutely nothing but his bed in there (no toys, books, furniture, anything he could try and play with), white noise machine, cool temps, thing on the doorknob so he couldn't get out, stick to a strict routine, etc, and a ton of sitting in there with him in the dark during the times he needed to be sleeping (we didn't do cry it out, though I would've if it came to that). It was hard for a couple years. I hope you can figure out what she needs so you can all get some rest! It seems like if nothing else, they eventually grow out of it and start sleeping well.