I'm a beginner, but the Tips and Notes have something about this. Best I understand, the possessive structure = definite article + noun + possessive adjective. Like here: literally, "the-girl yours"--article first, then noun, then possessive adjective.
The possessive singular should be correct. There is no way to determine without a visual in English whether the direct object is singular/plural/masculine or feminine. In the Deep South we distinguish you (sing) and "y'all" (plural).. or even "all of y'all"