“It means the name died out ...centuries ago, in the case of the Peverells. They could still have descendants, though, they’d just be called something different.”
-- Hermione Granger (DH22)
The eldest granddaughter of Ignotus Peverell, Iolanthe was from Godric’s Hollow. As the eldest in an all-female generation, she inherited the Cloak of Invisibility (Pm).
When reading Nature’s Nobility: A Wizarding Genealogy, Hermione discovered that the male line of the Peverell family died out quickly (DH22). But Harry remembered his lessons about the Gaunt Family in Dumbledore's pensieve and the fact that Marvolo Gaunt had the Peverell ring, so he knew the line never died out entirely (DH22,HBP10). In fact, Harry was indeed also a descendent of Iolanthe Peverell, who married Hardwin, son of Linfred of Stinchcombe, "The Potterer" (Pm).
Grandfather: Ignotus Peverell, creator of the Cloak of Invisibility.
Spouse: Hardwin, son of Linfred of Stinchcombe.
Children: At least one child, to whom she gave the Cloak of Invisibility.
"Iolanthe" means "violet flower" in Greek.
In a satirical comic opera of the same name by Gilbert and Sullivan first produced in 1882, Iolanthe is a fairy who never grows old.