I would definately go with a 20 or even a 410, 12ga loaded with Anything is going to kick alot for that small of a person and you do not want her to be scared of it. Mossberg's are great and TSG - Tactical shotgunner, a forum supporter usually has a maverick that is also of good quality (I hear) and are Very budget friendly. They also happen to have a pink 410 in stock as well... Patti is really easy to talk to and very informative, I'd look her up on here in the forum supporter section.