The friends I've mentioned dont have an attitude but tbh, there is minimal chance of them ever being short of money, so it's quite easy to be laid back about your 'entitlement' in those circumstances.
If they were in the middle of a divorce and thought they were about to lose everything maybe they wouldn't be so laid back.
I don't think you like this woman and that's up to you really. If you're sure she spent her dcs money on herself etc and is being grabby, that's understandable. But on the face of it, a high earner who works long hours paying the mortgage and bills is quite normal, BUT, what is unusual is you say he does the childcare as well? How is he doing that on top of the long work hours? Also, for a high earner, "hundreds" to his wife to spend on whatever isn't that unusual. Usually it's for outings with dcs and groceries etc. Not for, I don't know, hair extensions or a solo holiday or whatever.
It's really difficult to fully understand how other people's relationships work enough to go off a friend over it imo. But if you are in a position to know exactly what is going on and you believe she has shafted the high earning man, then, I'd say, that's an unusual situation, but you know them best