“Since car insurance often follows the car and not the driver, you would normally be covered if you borrow your sister’s car. However since you do live with your sister, insurance companies often require that household members be listed on a policy.
If you’re listed on the policy, your sister can either include you as a driver or exclude you from coverage.
If you are excluded from her car insurance
, you would not be covered by her insurance in an accident. If you aren’t listed on her policy and the insurance company finds out you live in the same household, they could deny a claim.
While it may increase her rates, adding you to her insurance would ensure that you and her vehicle would be protected in an accident. She can reach out to her insurance company to find out what the impact may be.