Imagine your house has just been cleaned by a helper. So after the cleaning finished, you check around if everthing was placed properly, and you see that a mat or (a piece of rug) that you normally use in the living room was mistakenly placed in another room.
Can I say it this way (pointing my finger at the rug):
It is not here's. It is the living room's. (as in the case of "It is not mine, it is hers.")