Is a girl considered sinful when she has sex at the age of 11 with an adult man, while she is unaware of what is permissible and impermissible at this age?

If a girl engages in sexual activity with someone other than her husband, and she is an adult of sound mind, then she is held accountable for the sins and transgressions she committed. This is based on the Prophet's (peace be upon him) saying: "The pen has been lifted from three: from the sleeper until he awakens, from the child until he reaches puberty, and from the insane until he regains his sanity." It is inconceivable that a Muslim would be unaware of the prohibition of engaging in sexual activity with anyone other than one's husband.

If the girl has not reached puberty, there is no blame upon her for what has passed, but she must be cautious in the future and not allow a non-mahram man to be alone with her.

However, if the sexual activity is with her husband, then a girl who has reached eleven years of age is capable of intercourse, and there is no harm in her engaging in sexual activity with her husband.