(a) Any person eighteen years of age or older may, by written agreement with another person at least eighteen years of age but younger than himself or herself, unless the other person is his or her wife, husband, brother, sister, uncle or aunt of the whole or half-blood, adopt the other person as his or her child, provided the written agreement shall be approved by the court of probate for the district in which the adopting parent resides or, if the adopting parent is not an inhabitant of this state, for the district in which the adopted person resides.

      (b) The Court of Probate may, upon presentation of the agreement of adoption for approval, cause public notice to be given of the time and place of hearing on the agreement. If at the hearing the court finds that it will be for the welfare of the adopted person and for the public interest that the agreement be approved, it may pass an order of approval of it and cause the agreement and the order to be recorded. Thereupon the adopted person shall become the legal child of the adopting person, and the adopting person shall become the legal parent of the adopted person, and the provisions of section 45a-731 shall apply.

      (c) A married person shall not adopt a person under the provisions of this section unless both husband and wife join in the adoption agreement, except that the Court of Probate may approve an adoption agreement by either of them upon finding that there is sufficient reason why the other should not join in the agreement.

      (d) When one of the biological parents of an adult has died and the surviving parent remarries, the person with whom the remarriage is celebrated may become an adopting parent without the biological parent’s joining in the adoption except to consent in writing. Upon the approval of the court, the adopted person shall be in law the child of both.