A guardian or conservator shall be allowed such compensation for his services as guardian or conservator, as the court shall deem just and reasonable. Additional compensation may be allowed for his necessary services as attorney and for other necessary services not required of a guardian or conservator. Compensation may also be allowed for necessary expenses in the administration of his trust, including reasonable attorney fees if the employment of an attorney for the particular purpose is necessary. In all cases, compensation of the guardian or conservator and his expenses including attorney fees shall be fixed by the court and may be allowed at any annual or final accounting; but at any time before final settlement the guardian or conservator or his attorney may apply to the court for an allowance upon the compensation or necessary expenses of the guardian or conservator and for attorney fees for services already performed. If the court finds that the guardian or conservator has failed to discharge his duties as such in any respect, it may deny him any compensation whatsoever or may reduce the compensation which would otherwise be allowed. The court may consider ties of blood, marriage or adoption, in making allowances of compensation to guardians and conservators.