Savannahs apear to be higly specialized invert eaters, in the wild they dont eat anything else then buggs. By the way I dont recomend getting something so big and strong for a 3 year old straigth away, even a gentle species such as this. Consider also that allmost all savs are wild cauth wich means they could have nasty bugs lurking in the mouth and claws. I would recomend that she waits longer for a big species such as this. By the way its important to say that no reptile is a kid toy, if there is going to be interaction adults have to be present at all times, the interaction can not go behond the reptile´s own patience and the kid has to be told to wash its hands. Has she considered a adult blue tongue skink, they are much easier to keep then beardys. Or a adult big tortoise like a red foot or a sulcata?