What's with Puerto Rico and Marie?

I'm sure it is deliberate. The realtor comments that there is at least one commemorative spoon for each of the 50 states. Marie's response is not out of the blue, but instead indicates that she noticed one of the spoons was from Puerto Rico rather than from a state. Rather than just say, "hey, that one isn't from a state like you said they were," she is a bit more passive aggressive in her response (while still being playfully banal) -- she's in essence undermining the realtor's knowledge of the house owner's collection by pointing out that it's not technically a collection consisting solely of US state spoons.

In the larger sense, I might even argue it's not a meaningless conversation at all. It helps build up the story arc of Marie trying to deal with Hank's depression from being home-bound. He won't let her take care of him, and belittles her at every turn, especially when it comes to his own collections, so as she goes from house to house pretending to be different people, she can escape being Hank's wife for a little bit of time. She can be Tori or Charlotte or whatever other alias she chooses ... someone who knows about Puerto Rico or who has a different job ... and the kleptomania that goes along with it (from this house, she takes one of the spoons, correct? Maybe it's the one from Puerto Rico) shows how she wants to hold on to the remnants of these other imaginary lives.