sorry - I should have clarified that gen-x kids were a 70s/80s thing, so by the 90s it was even more common.
Its late and I'm going to bed, but a quick search did turn up a bit more concrete data [0], it appears by 1988, 40+% of families were 'dual worker families'. It appears to be about 65% currently[1]. I'm guessing that would put it around 50% of families in the mid/late 1990s, so about a 15% change in ~30 years. I'd say 50+ percent counts as 'pervasive' in both cases.
edit: I guess the point I was trying to make is that both parents having to work is a pretty old trend, with the majority of families needing dual incomes going back decades - and really doesn't seem to be getting any better.
The fact that it was a specific term indicates it was a known thing, but at the same time not pervasive in the way it is now.