Tenn. Code Ann. § 20-12-129

A person acting as the next friend of an infant may on like terms prosecute a suit or appeal for the infant in forma pauperis, upon taking and subscribing an oath that the infant, in whose behalf the action or suit is begun, is not able, and has not sufficient property, to bear the expenses of the action or suit about to be commenced, by filing an accompanying affidavit of indigency as prescribed by court rule and that the infant is justly entitled to the relief sought, to the best of the next friend's belief.