She became part of the Hungarian nobility in 1912, when her husband was ennobled by Emperor Franz Joseph I of Austria.

Guinness, who met de László in 1892 in Munich while studying music, was the subject of a series of his portraits.

Guinness was born at Burton Hall, her family's country house in Stillorgan, County Dublin.

[3] In 1892, while in Munich, she met the Anglo-Hungarian painter Philip László while he was studying at the Royal Bavarian Academy of Fine Arts.

[3] Her family disapproved of her courtship with a student artist of humble beginnings, despite his early success as a portraitist, and so the couple parted ways.