Section 39. A guardian or conservator may make partition of his ward’s real property if lying in common and undivided, either upon petition for partition or otherwise, as fully and in like manner as the ward could do if he were under no disability, may assign and set out dower in his ward’s estate to any widow entitled thereto, and may appoint an appraiser of real property on an execution either against or in favor of his ward; except that when the guardian or conservator has an interest adverse to that of his ward no partition shall be made without the appointment of a guardian ad litem.