Caroline hasn't shown any desire to be human yet. However, here's what I understand. The thing about the cure is that if it gets sucked out of you, you end up aging according to your real age. So the older you are the quicker you age. So if Caroline drank it from Elena at this moment and then Stefan drank it from Caroline they'd both be human. And Stefan will be okay provided nobody drinks it from him otherwise he'd start aging like Katherine did. And if they had to wait for Elena to wake up in 60 years then only one could be human. Because if Caroline drinks it in 60 years and somebody drinks it from her she'll rapidly age too. So basically when Elena wakes up only one of the current vampires has the option of being human. And at the moment Damon has first choice. There's no way Stefan or Caroline would take it if there's a chance Damon wants to.