What is the ruling regarding a woman who cut a single strand of her hair out of ignorance after performing Umrah?

Shaving or shortening the hair is one of the obligations of Umrah, and shortening is prescribed for women, not shaving. Shortening must be done from all the hair, and this is the view of the Malikis and Hanbalis. So, if a woman has braids, she should take from the ends of all of them; otherwise, she should gather her hair and take from all of it. It is recommended to take the length of a fingertip, but she may shorten less than that, as no specific amount has been stipulated in the Shariah. Anyone who shortens from only one strand has not performed the considered shortening, and it is incumbent upon her to shorten her hair in the manner mentioned. There is no penalty upon her for any prohibitions of ihram she committed out of ignorance.