Oh no Nat, am just so sorry. Have just seen this thread. But on the upside, if she is bit better today that has to be good.
I think with babies everything is a bit soft and not quite stuck in as it should be. I cannot for the life of me remember what one of my baby thoroughbreds had on his hock, but I was so concerned that it was because I had put him and his friend out on a steepish field.
Looking back on it now, I realise that it probably would have happened anyway, and he still went on to race and was as sound as a pound.
Am sure Dolly will recover soon, remember, she is a big boned baby, and am sure she will be fine.