Aisha is the daughter of Paul Greyrat and Lilia Greyrat and the younger half-sister of Rudeus Greyrat. Raised by her mother, Aisha's personality is more of an adult than those of her age, being able to act and speak in a manner of a maid. She is smart, manipulative, cunning, and cute. She has a playful personality and may have a brother complex as she sometimes makes suggestive comments towards Rudeus and has no problems being naked in front of him whenever they take baths together.
(Source: Mushoku Tensei Wikia)