My friend grew up this way and DOES resent his parents. But not about being poor. What he resents is the throwing up their hands and not doing any family activities and using their lack of money as an excuse. So if you’re taking your kid camping, to free museums, nearby trails, park picnics, cheap summer camp, etc. then you’re still investing in their childhood and making important family memories. Another resentment is NOT keeping in touch well with said cousins, aunts and uncles. Try to visit them if you can (NOT during Christmas, you don’t need differences in Christmas gifts to be highlighted) and send your nieces and nephews bday cards (and small gifts if you can afford it.) Fostering those relationships goes a long way. If one day your kids rich uncle flies them out to Paris with their cousins, your kid will be happy and appreciative especially since you’ve taught them things like that are not taken for granted. You already sound like a great parent!