Linds, I was about this young girl's age when I got my first turtle, a RES (I know they aren't good beginners, but I learned a lot from her). I still have my Bo, and she's probably at least 13 + years or so old.
A lifelong companion was listed as a pro on my post. I believe the poster said this girl is very mature for her age, and capable of maintaining the pet. While I personally believe that an animal should never be given as a gift, if this girl wants a reptile most of her choices are going to be relatively long-lived; (Unless she gets an anole... or something along that nature). I was just trying to come up with a compromise - a reptile that's a little more acceptable.