Seriously...make sure she has a knife, then get her some training with that knife (even a one or two day seminar from a reputable instructor will do wonders). Make sure she carries a can of OC and understands its capabilities and limitations. And last but not least, look into some good quality empty-hand training.
And always remember: "concealed is concealed." If they don't know you have it, you have no problems. If they find out you have it because you had to use it to save your life...are you really gonna care?