My question would be, who's paying, and who's doing the work? When my younger daughter H became mad keen on guinea pigs it was logical to get the girls one each, but I knew my older daughter E, though a pet-lover, had waaaaaaaay more homework PLUS a hectic social life. So I had a chat with E about whether she wanted to take on the responsibility of a pet at this point and it ended up with the 2nd pig being officially mine, and so I share the work of feeding and cleaning with H.
But even then, pigs decide which humans they love and H's pig loves a long cuddle with me while H is at school (which we keep quiet about) and "my" pig shows a clear preference for the rare cuddles she gets with E!