Margaret was a girl from Noland who was more commonly known as Meg or "Fluff", because of her fluffy hair. She was the daughter of a ferryman, but became a Princess of Noland.
Meg was a sweet, pretty girl, with fluffy golden hair.
Meg grew up in a little village in Noland, nearly two days' journey from the city of Nole. Her father was a successful ferryman, and the family lived in a comfortable house on the river-bank. Meg had a younger brother named Timothy who was born when she was two; because she could not say "brother" at that age, he became known simply as "Bud". Their mother had died when they were young, so Fluff and Bud were raised solely by their father.
One night during a terrible storm, the ferryman was drowned trying to cross the river. His sister, Rivette, came to care for the children, but she was stern and quick to discipline them. Fluff was so upset, both by her father's death and her aunt's treatment of her brother, that she cried inconsolably night and day. Eventually Aunt Rivette decided to take Bud and Fluff to live with her in Nole, where she resided.
It was during this trip that a Fairy named Ereol came to Fluff and gave her a Magic Cloak that would grant each wearer one wish. Later that day, Fluff thoughtlessly wished that she could be happy again, and the wish was granted.
It was also on that journey that her brother Bud was selected to be the next King of Noland and Fluff was made a Royal Princess. They were taken to the Royal Palace where she was given forty new gowns and seven maids in waiting. (Queen Zixi of Ix)
Eventually Princess Fluff grew up into a beautiful lady. She married the ruler of a neighboring country and was well-beloved as their queen. (Queen Zixi of Ix)
Baum does not identify Fluff's royal husband. Nathan DeHoff marries her to Prince Bobo of Bobland in one of his Internet Oz stories, though this is later contradicted by The Royal Explorers of Oz trilogy, in which Bobo is single, and Fluff and Bud are still living in Noland. A re-writing of the DeHoff story is forthcoming which will retcon this discrepancy.