What is the ruling on plucking eyebrow hair due to a psychological problem, when all attempts to stop have failed?

Plucking eyebrows falls under the prohibited namṣ (plucking of hair). However, there is no sin upon your sister if she does so out of forgetfulness or inadvertence, or if her psychological condition removes her from the realm of accountability, such as becoming insane, or if she is a child who has not yet reached the age of accountability. This is based on the hadith (definition): "The pen has been lifted from three: from the insane person whose mind is overcome, from the sleeper until he awakens, and from the child until he reaches puberty." You must advise your mother not to go to charlatans.