That sounds like a great start! Are you still working with her PT wise to bring her head up manually? Would be good to give the muscles a little stretch so they don't forget where they're supposed to be able to go to.
It probably just got in a bad position in the uterus or birth canal and she probably just has a crick in her neck that feels better when she holds it down
So I won't keep boring you all, but look at her now. Sometimes patience is difficult when we want them to be healthy right away. She is not quite 100% but looking better every day. We think we will keep her.