Your translation is accurate, I would say.
Sir Joshua Reynolds and Thomas Gainsborough were the dominant British portraitists of the second half of the 18th century.
Margaret Gainsborough was the second daughter of Thomas Gainsborough.
See "The Artist’s Daughter Margaret".
oh i know, meaning they lived 200 years ago. inappropriate, magazine sheet which I found was so weathered.
@vcelier thanks for the enlightenment