Sobolev I.M. (40 years) and Petukhova V.V. (14 years)

Sobolev I.M. (40 years) and Petukhova V.V. (14 years old) decided to marry, but according to the law of the subject of the Russian Federation in whose territory they lived, the age of marriage could only be reduced to 15 years. Therefore, Sobolev I.M. and Petukhova V.V. came to Kovtun L.M. (Sobolev I.M.´s sister), living in Tyumen, and appealed to the City Administration with a statement on reducing the marriage age V.V. Petukhova up to 14 years old. The administration of the city of Tyumen sent inquiries to the parents of Sobolev and Petukhova (at their place of residence) and answers were soon received: parents of Petukhova V.V. on her marriage were agreed, but the parents of I. Sobolev categorically opposed his marriage to Petukhov. The city administration of Tyumen refused to reduce the age of marriage Petukhova V.V .; the refusal was appealed against by Sobolev I.M. and Petukhov V.V. to the Central Court of Tyumen, and citizen Kovtun L.M. (who sincerely wished the speedy registration of the marriage of Sobolev I.M. and Petukhova V.V.) filed a similar complaint to the Administration of the Tyumen region.
What should be the court decision and the response of the Administration of the Tyumen region?