"You have two sisters."
Translation:तेरी दो बहनें हैं।
Long story short, in Hindi the word for 'have' (पास) entails a sort of material possession that can't be applied to people. Therefore, the way of saying "You have two sisters" literally translates as "Your two sisters are". When you think about it, it makes sense. If I say "Your two sisters exist" then it must be true that you "have" them as sisters.
A bit unusual, but just a neat quirk of the language (the same is true for brothers, parents, friends, etc.).
Hindi has a case system that only applies to pronouns. For nouns, postpositions are used instead. तेरा is the masculine singular genitive case form of the pronoun तू. This is equivalent to using the postposition का with a noun. Similarly, तेरी is the feminine genitive case form of तू which is equivalent to noun+की and तेरे is the masculune plural genitive case form which is equivalent to noun+के.
So, 'You have two sisters'- तेरी दो बहनें हैं
'Neha has two sisters'- नेहा की दो बहनें हैं
'Neha has two sons'- नेहा के दो बेटे हैं
'You have two sons'- तेरे दो बेटे हैं