Kamakahelei was one of three daughters of High Chief Kaumeheiwa, the son of High Chief Lonoikahaupu and High Chiefess Kamuokaumeheiwa, and his wife, High Chief Kaʻapuwai, possibly the daughter of Peleioholani, Alii nui of Oahu and Alii nui of Kauai. According to tradition, her grandfather Lonoikahaupu was five generations in descent from the 13th Alii Aimoku of Kauai, Kalanikukuma. His family had traditionally ruled in Waimea and the south-western section of the island, although always in subordination to the elder line of Kauaian chiefs. It is unclear why Kamakahelei succeeded Peleioholani as the Aliʻi of Kauaʻi. It is not certain that she was his granddaughter or a close relative. The legends remain silent between the transaction of rule between the two dynasties.
She first married Kaneoneo, Peleʻioholani's grandson and the pretender to the throne of Oʻahu of the Kualii line. He had rights to the succession to Kauaʻi, but it is not known if he contended with his wife over the rule of the island. Kaneoneo's father, Kūmahana, was deposed by the ʻEwa chiefs, who replaced him with Kahahana. The latter was the last king of Oahu.
She and her first husband had two daughters: Lelemahoalani and Kapuaʻamohu. Kaneoneo died during the rebellion on Oʻahu against Mauian King Kahekili II in the year 1785 or 86.[1]: 297–298
Kamakahelei next married Kaeokulani, a prince of Maui and brother of Kahekili II. They had a son Kaumualii. Together they united rule of the island of Niihau, her husband's domain, and the Island of Kauai.[citation needed]