Case in point, my grandparents sent my kids $2 each in a Valentine's card. The 7 y/o then had the audacity to ask my parents why the Valentine from them didn't have any cash in it. This comes 2 weeks after my parents took my kids to Disneyland. (I wasn't doing so good on the "good grownups" front that day.)
Disclaimer: I have 7 years to go before I have a 7 year old, and it has been about 23 years since I was 7 myself, so my frame of reference here for how "with it" 7 year olds are is off...
But is this really "not doing so good on the 'good grownups' front"? From what I imagine a 7-year old's mindset is, great-grandparents and grandparents are sort of the same thing. If they get a card with cash in it, maybe the expect all cards from grandparents to have cash in it. Additionally, I don't think that a 7 year old will necessarily be able to recognize the huge cost of a family vacation.
I suppose it depends on the tone, and if there was a sense of entitlement with it, but on the surface it seems like a teaching opportunity rather than impertinence. After all, a 7 year old has 10-15 years before they're a grown up.
As an aside, now I'm smiling thinking about my Grandparents. Every time I came to visit, Grandpa wait til we were alone - could have been just passing in the hall - and slip me a bill or 4. Could have been $5, could have been $100, depended on what he had with him and how old I was and all that, but you could tell he always felt like a big shot doing it. And all of us grandkids thought he was too, because for us, he was. He told us all that the "walking around money" was over once we were 18, but I don't think that was true for any of us as he bent the rules every time, and if he didn't, Grandma did in cards... Halloween Cards, Easter Cards, Thanksgiving Cards, St. Patricks Day cards (we're not Irish, or even "Irish on St. Patricks Day")... I think I once got a Flag Day card from her with a tenner in it. Had no clue there was such thing as a Flag Day card.