Guinea pigs are much hardier and easier to handle
Guinea-pigs are not hardy they need protected from everything
Heat , cold, damp (it can easily kill them) predators.
They need the right diet .
They can get ill and die very quickly , you need to know their habits . (I knew one of my sows was ill because she sat differently and wouldn't join her cagemates . There was no animosity , she just took herself off and sat gently 'nodding' )
You need a good Guinea Pig Savvy Vet . They don't need vaccines like rabbits do and they don't need neutered unless you want sows+boar (only one boar in a mixed group . Or 2 boars as a pair , not more)
They are (and I say this with great love as DD and I adored our piggies) Just A Bit Dim.
But they are chatty , greedy , messy , interactive, defenceless little rodents who rarely (not never) bite . And I'd state hand on heart that if you get bitten it is something you've done ( obviously if its your first pigs don't get wild ex breeders , one of mine was a mouthy little toad who gnawed and had claws like knives . But I'd asked for feisty , our boar was a huge 1.4kg young boy)
If she really wants rabbits , make sure she won't feel fobbed off with guinea-pigs
Make sure she's not allergic to fur or hay
Though my DD developed an allergy to 2 of her coarse coated pigs
She looked after the school rabbits (in the school not our house) and much preferred our pigs
And I'll leave you with this thought :
No matter what she says now , how much she promises , there will be times that she won't look after them.
DD and I shared the piggies (and I offered to swap one of mine for her allergenic boar but nope) So if she said "Mum I'm doing something , I'm ill, I'm staying at a friends" then I did it . Just as easy for me to tend to all of them while I tended to mine . But next day , she did the care > My daughter isn't an angel and I only sometimes felt taken advantage of 
If it happens that she doesn't you , as the adults , step up . No question. The animals are legally yours , she is 10 .
And rabbits will be with you when she's left home
Piggies too , you'll get into the spiral of One Dies/You Get Another as company .