Funny, but less conventional pets -- and reptiles are really not so unconventional anymore -- can often be good ones. Rats have the association with pestilence, but when domesticated and bred, they are smart, friendly, and companionable in many cases, and they are much smarter than you'd think. Wild rats find their way into labs housing rats to get food and romance, and do so for long term despite pest control efforts. The only aspect I'd adamantly avoid is bonding with venomous snakes. A local, well-published writer here was an avid rattlesnake man and was forever getting bitten, and stopping off at a bar for a few drinks before going to get treated. Your daughter looks entirely pleased with her friend, and will learn a lot from keeping such a companion animal. Oh, and I meant to mention, in UK and maybe other places, there is an actual rat fancy, like a cat fancy, where rats are bred for specific traits, groomed lovingly, and shown in competitions like cat shows. This would seem bizarre to me, but having kept hamsters as a child, and having known about rats from my work place (labs) I understand this a little better. Rats are quite thoughtful; who knew? This snake makes me think of the really huge snakes I've seen at zoos, the anaconda; those things are immense, and have been known to eat the occasional human, though only for special occasions.
They’re cool animals, but a game of fetch would be very one-sided I think ?