What is the ruling concerning a second 'Umrah for an elderly woman who forgot to cut her hair during the first 'Umrah, then entered into a state of Ihrām for a second 'Umrah in the same clothes, unaware that the Prophet, peace and blessings be upon him, never performed more than one 'Umrah on the same day, and she cut her hair after the circumambulation (Tawāf) and before the ritual walking (Sa'ī) in the second 'Umrah with the intention of exiting the state of Ihrām from the first 'Umrah?

Shaving or shortening the hair is a ritual of 'Umrah, and one cannot exit the state of ihram without it. Therefore, when your mother remembered and shaved her head, her first 'Umrah was completed. Her entering into ihram for a second 'Umrah before shaving was void, as she was still in the state of ihram for the first 'Umrah. Consequently, by shortening her hair, she completed only one 'Umrah, which was the first one. Repeating 'Umrah during the same journey is permissible, though refraining from it is preferable.