Paul's cat and Rémy's dog

Whose cat is it? It's Paul's.
                            (It is Paul's cat)
Paul's lucky because he's got a lovely pet.
(Paul is lucky because he has got a lovely pet.)
Attention 's peut signifier trois choses différentes.

Whose dog is it? It's Rémi's.
Whose drawing is it? It's Rémy's. CONGRATULATIONS!

Quelle est la valeur du's dans les phrases suivantes?
1-John's sister's a reporter.
2-Martin's got two brothers.
3- Coline's cake 's delicious.
4- Pauline's school bag's heavy.
5- He's got a big house.
6- It's my sister's cat.