There are possessive pronouns which are " your , her , his ...etc", and there are possessive nouns that show the possession or ownership. They can be singular and plural,but in the possessive they are used as adjectives to modify another noun. To recognize possessive noun it's easy cuz always it shows an apostrophe and the letter (s) .
For example :
(singular ) The cat's fur is so soft.
(plural ) The cats' fur is so soft. < if the noun ends with 's ', you just add apostrophe . If it does not end with 's' just like 'women, mice ' the irregular plural nouns , you add apostrophe with 's'
I hope it's helpful . Good luck