I think they do accord more importance to grooming and looks than British women, yes, on the whole. Women politicians are generally sleeker here, though I think Dati pays particular attention to clothes and appearance.
As for me, it's hard to say; I left the UK at 21, just after graduating, and moved to a French island in the Indian Ocean, where the heat makes chicness more tricky. The shift from student status to a working one meant that I necessarily changed style a bit, and the climate caused me to be more careful about hair removal, etc. than in Scotland!
14 years down the line, I've been in mainland France for 3 and a half years and I'm not particularly groomed, I don't think. It's partly due to having wild curly hair, which never looks sleek or chic. I also work in an environment where people dress fairly casually (but probably better than many female academics in the UK, though I couldn't be sure). I do notice when I go back to the UK that British women, when they are not dressed more casually than French ones (comfy fleeces, tracksuit bottoms, etc.) have more of a tendency to wear what's in fashion or to go for a style they like, irrespective of whether flatters, suits or even fits them, whereas many French women tend to choose things more carefully. And while things are changing fast, there are fewer overweight women in France, so clothes often hang a bit better on them. I have started wearing minimal make up, which I didn't do before, but that's more to do with age than location, I think.