Daisy Pennifold was a witch who lived in the 18th century. In 1711, shortly after the change in colour of the Quaffle, Daisy invented a charm to slow the target's descent and used it on the Quaffle, allowing Chasers to retrieve the ball while it was still in the air rather than having to dive to the ground. These enchanted Quaffles became known as "Pennifold Quaffles" and are still used in modern times.
The name "Daisy" comes simply from the English word for the white flower, ultimately derived from Old English dægeseage meaning "day eye". It was first used as a given name in the 19th century, at the same time many other plant and flower names were coined.