It really depends. If the SoL is responding to OP's remarks on her families current life situation by talking about how she and her spouse can't afford their nth honeymoon to the Bahamas... That's pretty spiteful. It sounds like a communication failure on BOTH sides, to be honest.

It will get better soon OP :)

I think this depends a lot on context. If she's saying "You know, that second yacht is so much hassle! I do wonder sometimes whether we should just ditch the place in Monaco and get one in the Caribbean instead" then you know she's just doing it to show off. It's not necessary to be so unfeeling.

Slap her upside the head and tell her to say three nice things about her life everyday until she feels grateful for it.