A testator may by his or her last will relieve the conservator of his or her appointment for a minor child or children from giving bond and sureties for the faithful performance of his or her duties as conservator, but the authority of such conservator shall not extend to any other property or estate of such minor child or children than such as is derived by gift, devise, descent, or distribution from the testator, unless he or she gives bond, with sufficient sureties, as is required of other conservators.