Is it permissible for a mother to disinherit one of her children due to his theft from her, and distribute the rest of the inheritance among the remaining children, with the male receiving the equivalent of the share of two females? And would she incur sin for that?

Theft is not proven merely by claim or suspicion, but rather by testimony or the thief's confession. If it is proven that the son stole from his mother and she could not recover the money, she is permitted to reclaim it by any possible means. If the theft is legally proven, then the heirs have the right to demand the stolen money from him. However, if the theft is not proven, the inheritance must be divided legally among all heirs, including the accused son. In the event that the heirs are two sons and a daughter, the inheritance is divided among them by ta'sib (agnatic succession), with the male receiving the share of two females, meaning five shares: two shares for each son and one share for the daughter. The matter of inheritances is serious and complex, and a mere fatwa is not sufficient; rather, it must be referred to the Sharia courts for investigation and to ensure the rights of all.