Through her mother, she descended from Keaweaheulu and Kameʻeiamoku, the royal counselors of Kamehameha I during his conquest of the Hawaiian Kingdom from 1780 to 1795. Kameʻeiamoku was one of the royal twins along with Kamanawa depicted flanking the Hawaiian coat of arms, and his son Kepoʻokalani was the first cousin of the conqueror on the side of Kamehameha's mother Kekuʻiapoiwa II. Their family were collateral relations of the House of Kamehameha and ascended to the throne in 1874 upon the election of her uncle Kalākaua as King of the Hawaiian Islands. Her mother was a younger sister to Kalākaua and Liliʻuokalani. Kaʻiulani's father was a Scottish financier from Edinburgh; he served as Collector General of Customs from 1887 to 1893 and as the final Governor of Oahu from 1891 until the office was abolished by the Provisional Government of Hawaii after the 1893 overthrow of the monarchy.