My sister co-signed for my house loan, and recently is in need of a car loan. She is worried that co-signing will not allow her to receive a car loan now. We are wondering how long before the loan will appear on her credit report?

Also, how long before I can get her name off my loan?

Usually a month or so. A couple weeks after the first payment is due.

How long? How long before you are able to refinance the house on your own? That's the only way to get her name off it.