Goldberry
From Tolkien Gateway
Goldberry, also known as the "River-woman's daughter" (or "River-daughter"), was the wife of Tom Bombadil.
Although her origins are uncertain, it has been speculated that she is a river-spirit of the river Withywindle. Otherwise, she and Bombadil are enigmas in Tolkien's Middle-earth legendarium.
In Tolkien's The Adventures of Tom Bombadil the first poem tells the tale of her "capture" by Tom Bombadil.