I'm from Ireland while I'm not going to pretend that's the same in terms of culture, because NI was unique, I don't think it was particularly different fashion wise. My working class parents were 36 and 37 in 1997. I was 18. My parents looked absolutely nothing like people in their late 40s and 50s. Women that age, of our socio-economic status, wore mostly jeans and jumpers, shorts and t-shirts and skirts and dresses, just like the rest of us. They wouldn't have been on trend because they couldn't afford to follow fashion so would have more classic than very wide legged jeans in the early 90s or bootcuts in the late. My mother went grey earlier than her peers but even still at 37 her hair was still mostly blonde, occasionally box died with a level 2, and cut mid-length in layers, just like pretty much everyone else from 12-50 at the time. The only mothers of friends I knew who had an 'Irish Mammy' cut were those who's mothers were very significantly older and nobody under 60 allowed themselves to go grey.
There was still something of a fashion divide between people my age and hers. Knee high boots with short skirts were coming into fashion and I'd have died if she'd ever dressed in anything like that, whereas when I was 36, that was still fairly normal wear. People her age wouldn't have shopped a lot in the likes of Swamp, Japan, Top Shop, etc. Because they didn't wear cheaply made clubwear. But at the same time I shopped in a lot of places she did and a lot of my regular day to day wardrobe would have been the same as that being worn by people her age.
It was the late 90s. People often talk about that time as if was such a very, very different, backwards era. And while lots of things have changed since then, it really wasn't as different as people seem to think it was. Buffy premiered in 1997 and honestly, Joyce Summers, Buffy's mother, is a good reflection of what most mothers I knew in the late 90s looked like.