Gaia

Gaia is Kai and Toby's mother. She left the island at a young age when her mother fell out with Nonno, and returns at the end of the story when Nonno's health hits a crisis.

History
Gaia is Nonno and Dora's daughter, and was born in a city. The family moved to Mutazione when her parents' Expedition of Scientists looked for ways to study (and perhaps exploit) the island. Gaia was brought with, and was primarily supervised by her father while her mother worked.

Gaia befriended the Dots at an early age, and made great efforts to be fair while sharing fruit with them. She met Claire the summer before she left, and the two were close friends. In the years after Gaia and Dora leave the island Gaia and Claire become penpals, continuing to write even into adulthood. The two of them are glad to see each other when Gaia returns, and they spend time catching up.

When not on the island, Gaia works in an office as a successful architect.

Two years ago she lost her husband in an airplane crash, and is now a single parent to her two kids.

Gardening
Though we never see her garden on-screen, Nonno tells a story of having taught Gaia how to garden at an extremely young age by letting her plant weeds. Gaia took the task very seriously.