She should grow them back when she molts. You could put a hen saddle on her to protect her back, if she's the rooster's favorite gal. Believe it or not, hens will wear those saddles and they look cute and comfortable. Look in the sale section, and members here make and sell them very reasonably.
I don't think, in my humble opinion, that I would use vasceline on the wound. It seems like that would make it sticky, and then with chickens, even more dirt will stick to the wound. I use a spray called Blue Cote. It seems to work well, although I have to say I've had very few wounded birds.
Also, something to consider might be trimming those spurs on your rooster, if they're getting real long. You can look that up on U-tube, and they can show you exactly how to do it.
Good luck with your hen!