She chose each moon carefully. After all, the tree was far out in the field. Her moons had to do more than light up the surrounding area, they had to guide her to and from the tree.
It had taken her years to find them. She wanted moons that gave off a blue white hue, so that meant she had to look for moons near younger stars and such star fields were often protected on the off chance they would cool down enough to support life on nearby planets. She also wanted moons at their fullest to maximize her light. And then there was the added issue of what the moons were being used for.
Guardian texts could only be read by moonlight, a result of the Guardians' mission to look after the universe. Moonlight was a renewable energy source after all. And the choosing of moons to read the texts by, based entirely on instinct, served as an aptitude test. It was rare that the moons of a moontree weren't replaced to better align with the Guardians' teachings as a student got deeper into the texts. Kayla wanted to replace none of them and so debated over each moon to use.
If that meant she started studying three years after her peers, so be it. But she was planning on being the best Guardian of all time.