This is a question we get from DD (9) and I find it really hard to pitch the answer. I'm not giving actual figures, because she would tell people, and I also don't want her to get the wrong idea - her friend thought she (the friend) was going to be rich, because of a Junior ISA of a couple of thousand, which to a 9 year old feels like a lot, but the friend thought this would be enough to get a house, car, etc.
DD asks 'are we rich, or poor?' She's a bit of a social warrior. She knows we are better off than, say, homeless people, but somehow it hasn't occurred to her quite how well-off the family is (family money, multiple holiday houses) and I find myself very reluctant to tell her. We live in a well-heeled area, and her friends' parents are mainly lawyers, hospital consultants etc, so a certain level of income is considered 'normal' in her peer group, though it's high for the general population. We've got extra beyond that, but not in the super yacht class! We do make sure we sometimes say no to certain treats, or explain that we've spent a lot recently, even if we could ultimately afford things, because we don't want her to get spoiled or see money as a bottomless pit.
I'm trying to instil a sense of responsibility for those around us, whilst preparing her to one day come into a pretty decent inheritance, whilst trying to make sure she makes an effort to be independent.
I think my usual answer is "we're very lucky, but it's always good to be careful with money, save some of it etc. And there will always be someone richer."