Hestia [aka Vesta] The Hearth-goddess and daughter of Cronus, she swore to remain a maiden forever after Apollo and Poseidon tried to win her hand. Zeus then bestowed her with the title of chiefly worship of the family Hearth. In later versions she would become the hearth-goddess of the universe and become the personification of earth as the center of the universe.
I agree with everything except the Little Mermaid reference. Triton was Poseidon's son, not a derivative of Poseidon.