Can you use your in third person?

No, the pronoun 'your' is a second person pronoun, a word that takes the place of a noun for the person spoken to.
The pronoun 'your' is a possessive adjective, a word that takes the place of a possessive noun to describe something belonging to the person spoken to.
A third person pronoun is a word that takes the place of a noun for the person spoken about.
The third person possessive adjectives are: his, her, its, their.

Examples:
Your mother is very nice. (second person, the mother of the person spoken to)
Have you met Jim's mother? His mother is very nice. (third person, the mother of the person spoken about)
The door needs repair. Its hinge is cracked. (third person, the hinge of the door spoken about)