The dad’s brother paid for the Paris trip. He had been watching his niece (the older one that counts everyone) while he worked in Paris, and in exchange the brother paid for them to go to Paris for Christmas (and also no doubt so he could see his kids). The brother is loaded, as we also see in the second move, he is remodeling a New York brownstone in midtown.
That says, they do pretty well. It may even be the mom with money. There is evidence to suggest she is a fashion designer with all the mannequins in the house. But the following year when they pay their own way, they go to Florida and not Europe, so they are probably not as loaded as his brother.
Rich people go to Florida too. Also I have known a few fashion designers and they generally fell into the pretend job category. I'm sure there are hard working career focused designers out there, but there are a lot of dilettantes half-assing it as well .
$122.50 and she's apparently a crappy tipper, which leads me to believe that she's more likely to be the main breadwinner than he is. I delivered pizza for years, and noticed some trends based on income levels/ wealth levels.