I think I would just leave it alone. As it grows you may need to file that one point down on the side if it's a risk for getting caught on something, but she may hone it herself. It may be tender for a few days, so feeding a mash by mixing some water in the feed may help her, and feeding in an open dish, and raising feeders and waterers up to shoulder height so she can scoop more with the lower beak. It should harden/dry up, and then will be less painful. Since it looks like the quick has not been damaged it will probably grow out eventually and be fine, but will take a while. They often get injuries like that from putting their beak through wire to try to get something on the other side. Or getting caught on feeders or waterers. So check those things. I've had roo's do it fighting.