What Italian Baroque painter and printmaker became known for her ability to so quickly paint beautifully finished canvases that many visited her studio to watch her work?

What artist was one of the most renowned and universally admired painters of late 19th century Britain, so identified with that period as to later be consigned to relative obscurity?

Answers here~ https://schristywolfe.com/2016/01/08/january-8/