I won't go so far as to say lucky, but it could have been worse. If he hadn't hit her, it would have been a lot better.
Going to a mountain bike and cycling off road, she's going to have to learn some new skills. From my own experience with this transition, a) roots look like sticks but act a lot different under your tire - the sticks will roll, b) learn to go between the trees (not an issue in road biking).