Wellington is the first foal of Mihiri (More Than Ready), who was Group 2-placed in Australia. She has since produced winners in Australia by Star Turn and Star Witness.

Second dam Danoise (Danehill) never raced and produced six foals and four winners, Mihiri the best of them. She is a half-sister to eleven winners, notably Cerulean Sky (Darshaan), winner of the Gr.1 Prix Saint-Alary, dam of the Group 2 winner and sire Honolulu and grandam of the Group winners Royal Bench, Mayhem and Memphis Tennessee, Moonstone (Dalakhani), winner of the Gr.1 Irish Oaks and dam of the Group winners Nelson, US Army Ranger, now a sire, and Words as well as two Listed winners, and the Classic-placed Listed winner L'Ancresse (Darshaan), dam of the Group winners Master Of Reality and Sibila Spain.

Third dam Solo de Lune (Law Society) was Listed-placed. Her other foals include the Listed winner Diner De Lune (Be My Guest), the Group 3-placed Demurely (Galileo) and Qaatef (Darshaan), and the Listed-placed Claire De Lune (Galileo) and Bywayofthestars (Danehill), dam of the Group 3 winner Orchestra.

Mihiri has a yearling full sister to Wellington.