I don't think comments like
"most of them mention the artist's gender: "It would be a remarkable painting if it had been by a man, but it is extraordinary because it is by a woman"—that kind of remark."
are necessarily sexist or to be otherwise reproved, it was very unusual for a woman painter to be able to make a living as a painter until well into the 20th Century.
Like the male painters, it certainly helped if you were gay, and this lady (from the contemporary descriptions) certainly was.
Gay male painters weren't saddled with the burdens of earning enough money to feed a number of mouths and could flit from city to city, chasing commissions, as Da Vinci did. Their liaisons and love lives didn't end up in fatherhood, mortgages, rent, school fees, years of worry, stress and all the other attendant by-products of fertility.
Gay female painters (and poets, musicians, etc) were similarly unencumbered, happy to be labelled 'maiden aunts' into their dotage and able to concentrate on their work.
