If it be clearly shown by the pleadings and proof that the interest of the person filing such bill will be promoted by the sale, lease or other conveyance of the property, and the court shall be of the opinion that the interests of no other person or persons in the property will be materially injured or prejudiced by such sale, lease, or other conveyance, the court may, with the consent of all persons in being having any vested estate or vested interest in such property, except in certain cases provided for in section nine of this article, in which case such consent shall not be necessary, decree the sale, lease, or mining lease of such property, or of any interest in such property, in such manner and on such terms, and in such parcels, as may be deemed beneficial to all persons interested: Provided, That where any party having a vested estate or vested interest is an infant, or insane, or convict, the guardian of such infant, whether testamentary or appointed by a county court or the clerk thereof, or the committee of such insane person or convict, may consent for such infant or insane person or convict, as the case may be; and any married woman having an interest in the property may consent without the consent of her husband: Provided further, That the consent of no person having a merely contingent or executory estate or interest shall be necessary in order to enable the court to decree such sale, even though such person having such contingent or executory estate or interest is a necessary party to such suit: And provided further, That the consent of no holder of any lien or encumbrance created since the twenty-second day of May, nineteen hundred and eleven, shall be necessary to any sale, lease, mining lease, or other conveyance made under the provisions of this article: And provided further, That if any person in being having any vested interest in such property shall not consent to such sale, lease, mining lease or other conveyance, the court may nevertheless decree such sale, lease, mining lease or other conveyance, to be made subject to the interest of such person in being so refusing to consent.