Yes, your company still must cover her as long as her permanent residence is your home. Even if she doesn’t have a vehicle with her, your policy covers her for liability when she may borrow a vehicle at school and when at home on visits.
Showing proof of insurance with another company can help you remove him. Also, show the company any documents that will help prove that a change of address has taken place. Examples of these documents can include lease agreements, utility billings or receipts, and a current driver’s license.