Is it permissible for a 26-year-old woman who desires to wear the hijab to travel to perform 'Umrah without a mahram, but with a religious girl, knowing that her mother refuses her wearing the hijab and only permits it after marriage?

If the purpose of the hijab is to cover the body except for the face and hands, then a woman must wear it, and it is not permissible to obey her mother in abandoning it, as there is no obedience to a creature in disobedience to the Creator. If the purpose is to cover the face, the matter is less stringent due to a recognized difference of opinion. As for a woman traveling for an obligatory Umrah with a trustworthy company, it is permissible. It is advised to strive to find a husband.