If you reside with your mother, she will need to list you as an 'eligible driver' on her policy. If you do not live with your mother, you do not drive the vehicle with any regularity, and you will be driving her vehicle with her permission, you should be covered on her policy. However, to make sure you are adequately covered, you can purchase a "non owner" policy. Many insurance companies offer "non owner" policies to people who drive occasionally, but do not own a vehicle. These policies typically include liability, medical payments, and uninsured motorist coverages.

You should contact your mother's insurance company to make sure you have coverage for the 3 days on her policy.