I think it depends on where you live too, skinny (as in thinner than average) being a relative measure.

I live somewhere extremely skinny by global standards and she wouldn't be called skinny, people might say, "yeah I guess she's skinny" if asked, but she wouldn't be seen as "a skinny person" because she wouldn't be far off the average. Same way a 5'8 woman wouldn't be a "tall woman" in the Netherlands.