These ppl are weird. It's not just about money, it's about the fact that they are filling landfills with couches. Buying cheap is stupid and half their problem. Buy more expensive, it's durable, it will las twice as long, you've got half as many couches filling up landfills. You buy durable ugly couches and it doesn't have to be that expensive. Lasts two to three times as long, reduces the cost. You don't pay any more money, you simply stop filling landfills with cheap couches that Priscilla likes.
Our living room sofa & chair are 17 years old. We just replaced the couch in our TV room which was significantly older than that. We do not have anybody in our house that does what Abbie does of course, and that matters. There is probably no couch, expensive or cheap, that will endure what Abbie does, but that just means they need to do workarounds. There are couch covers which would help, but they'd be pretty ugly b/c you'd have to put it b/w the cushion and the bottom. Thick plastic was a thing I've seen people do before. Not pretty, but you're not going to throw away a sectional every 2 years.
Failing all of the above, isn't the obvious solution to get the girl her own chair? Which they can then trash every two years? Why are they buying large sectionals and throwing them away every 2 years because one person?