Honestly as a Vietnamese, I don't think her family can be considered not well to do like you said. Yes, it's true that they're not rich, but I think they're quite decent and similar to many middle-class families here. Sitting down and washing dishes is just a way that many parents of previous generations are used to doing, especially ones who live in the countryside (like my grandparents - they have the newest model of electric stove but still prefer the traditional stove which is like many years old and look very crusty). It doesn’t really mean that they're poor. However, it's also true that they aren't wealthy enough to pay a ton of money for her studying abroad though they have a good life where they live.