She clearly is. But I find it forgivable, since the article is actually fairly interesting.
And unlike most people who use the term "sexism", she actually carefully defines her terms. If a normal person says "a pullup bar is sexist", we'd think they are crazy, since we'd be find the moral judgements that person is making to be nonsensical. But because we know her definition, we can simply acknowledge "by your unusual definition a pullup bar is sexist".
She has helpfully enabled us to avoid falling into this trap: http://lesswrong.com/lw/np/disputing_definitions/