Fellow long term guinea-pig owner here .
I have two cats ( who are more independant but less friendly)
No way would I have had guinea-pigs and cats together , it isn't fair on either .
Guinea-pigs are amazing little animals but they are considered Exotic by Vets for good reason. You need to protect them from everything
Cold. Damp. Heat. Draughts . Can all kill them.
They need careful handling especially by children. My DD was 9yo when we got her boars .
They need a careful diet including loads of hay (messy) unlimited .
Vit C in veg and pellets
They cannot vomit . They are prone to bloat if they overdo grass
*They don't kick, jump, run fast or climb ( *some can do all of these though )
And though they have big rodenty teeth they rarely bite . Usually if they do the human deserves it .
You always get to the stage of one dies and you need another (The Guinea Pig Spiral) Our last three oldies were a boar (he'd lost his wives) and two bonded sows (who wouldn't bond with the boar) Over six months we lost one sow , married the other two , lost him then the last girl . She was our last one we decided we'd come to the end of piggies DD was 16-17 so I didn;t want more .
Your DD will say she;ll look after them and no doubt she will . But there will be times when you need to .
DD and I shared the guinea-pigs and the work . Sometimes she was at a sleepover , ill , doing himework . If that was the case I did them all ( we had 8 over eight years , at one point 5 in our herds ) .
They aren;t the most dynamic or exciting creatures .
But seeing them dive into clean fresh haybeds , wheeking with joy . Or going out into their grass runs .
Made my heart leap .
Those tiny piglets in P@H in the perspex tanks . They look no trouble . But they grow . They are so so untidy (hay bloody everywhere) and they shouldn't be on shavings or sawdust , bad for their breathing .