Who is beatrice in series of unfortunate events?

Beatrice Baudelaire was the youngest of the Baudelaire children's parents, and the younger sibling of Bertrand Baudelaire. She married Bertrand and had three children: Violet, Klaus and Sunny Baudelaire. She and her husband died in a fire that supposedly claimed the lives of all three children as well. Count Olaf, believed by the Baudelaires to be the cause of their parents' deaths, was placed as their guardian.