Yep! My lovely sister, who is married to a CEO, lives 10 minutes from me in a $1 Million dollar home, has extensive renovations ongoing, a trip to China, or Africa, or Europe for 3 weeks once a year, a trip to Hawaii for 2 weeks once a year, and a couple of small trips in between.
They have season ski passes, kids are in team sports, and the kids have very, very nice gear and clothing.
What this means for me?
I am so happy for her. We get awesome clothing hand-me downs that are fabulous for the kids. She is stay at home mom, that still puts in a ton of effort with volunteer, taking care of her MIL, shuttling kids to all their activities, and keeps her house very very clean. Because of my BIL job and family focus, she entertains a LOT. As in 20 people just showed up at her door and 16 of them are staying for the next 5 days.
My kids? Never really mention it or notice. What they DO notice is when Grandma and Grandpa spent far more time with their cousins. Then we also moved 2000 miles to be within 10 minutes, and our kids are so happy, money is no difference at all. They love swimming in their pool, for example.
On the other hand.... I think my kids have noticed (the mini MMM's that they are) that my SIL (other side of the family) and kids get a lot of handouts from the other grandma, because they "don't make as much money". It is actually "economic outpatient care" in that family situation, and the result is that although they actually make within $10k of our family's income, they have a ton more "nice" stuff, fancy foods, etc., courtesy of Grandma and SIL constant asking..
Moral of the story?
My kids picked up on "you get what you earn". No jealously if they can see how a great job and hard work pays off. Jealous when they see their other cousins getting stuff that they did not earn.