ScarletArboretum
I kind of agree that the best option is to just keep Ain awake and get rid of all the enemies, but it would be really boring. I recommend forging an artifact, putting all the spiritual energy she have into said artifact, and using that to cultivate become a dual cultivator, cultivating both the physical and essence. This would be more beneficial in the long run as she would eventually leave the world of One Piece and it is usually almost impossible to start cultivating something new after a certain level (usually the immortal/divine level). If she gets the Ain fruit, she could make something like a living artifact and use the fruit to regenerate the artifact's celestial energy. If she is willing, she could even refine Ain into an artifact, but it seems very demonic to Cherry and considering her cultivation level it may have more than enough energy to use for a few centuries and even reach a stage where she can generate the celestial energy alone or by other means.