A married person, whether a resident of the Commonwealth or not, may, by power of attorney duly executed and acknowledged as prescribed in § 55.1-612 or 55.1-613, appoint an attorney-in-fact to execute and acknowledge, for him and in his name, any deed or other writing that he might execute. Every deed or other writing so executed by such attorney-in-fact in pursuance of such power of attorney while the same remains in force shall be valid and effectual, in all respects, to convey the interest and title of such married person in and to any real estate thereby conveyed or otherwise transferred.