Welcome to the board, b33p3r.
Probably wouldn't be a bad idea to have your dog back to the vet again for a reevaluation. Was her had actually pinned to the ground by the tree? Could she have injured her trachea or larynx during the accident? And did they do xrays of the neck to make sure none of the vertebrae were damaged?
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."