You said "owned" as in they don't have one anymore? Just to be clear do NOT put the chin with a rabbit, the rabbit would likely kill the chinchilla. It's not even really that safe to keep rabbits and chinchillas in the same room since rabbits can carry bacteria that is deadly to chinchillas.
If you mean the human would need to bond with the chinchilla in order to take care of it, not really. You don't really need to have a bond with an animal to feed it, water it, and clean the cage. I just wouldn't suggest they take it out for playtime if they can't get it back in the cage. I would suggest if possible who ever you go with meet Willow before you go away though. That way they can learn how you do things (if there is anything the chin specifically likes or needs done, etc) and the chin gets to meet who will be caring for her.