A handgun is the best option. She has choices that may appeal to her. Her first round in the clip can be a non-lethal round. This gives her the ability to protect herself from a legal stand point, as well as from an emotional one. If she fires off a non-lethal round, that gives her attacker one more chance to make a decision against attacking her. It will hurt him, but 9 times out of 10 it will not kill him. At that point, if he persists, she can take the next step with a clear conscience that she did everything possible to avoid injuring or killing him. Legally, she is also protected if her first shot was a non-lethal round. This offers more protection for her in the event that her attacker's family tries to sue. These rounds can be found online for around $14 for 6 shots.