You should contact your insurance company to determine if she would be covered on your policy. It may depend on where she lives.
It is better that you add any drivers to your policy that may drive your vehicle on a frequent basis.
If you give her permission and in the event of a claim, she is not excluded or "not covered" on your policy, then she should be covered, but it is up to your specific policy. Some policies have broad exclusions for drivers in certain classes (classes are defined in your policy).
For example, some policies define a driver class as any driver under 25 years of age that is not listed on the policy.