It hurts her credit if she closes the account. Just add yourself and you'll have established credit history.

 

But I've never understood why people give the advice to only have one credit card. There's nothing wrong with having 5-6, as long as you are smart enough to not go and charge them all up. Low utilization is a good thing.. and having more credit will keep your utilization lower for those times when you do need to charge something on your CC's.

 

he's right. too much utilization or too much revolving debt counts against you.