Any member or officer of the National Guard of the Virgin Islands may give a power of attorney to be exercised during the period which the donor shall be on Territorial Active Military Duty or Federal Active Duty. Such a power of attorney shall continue in full force and effect until revoked by the donor or by operation of law. The donee of such a power of attorney may act for and represent the donor to the extent as authorized in such power of attorney provided that nothing in this section shall authorize a donee of a power of attorney given by a minor to sell, mortgage or dispose of the property, real or personal, of such minor.