Is it permissible for a woman to travel with her daughters by bus for 24 hours if the travel is necessary to renew their residency and there is no mahram present, and is this journey considered a necessity?

A woman's travel without a mahram is not permissible by any means, due to the general prohibition in the hadith: "No woman shall travel except with a mahram." Some scholars have, however, permitted her travel without one if she is in a secure company or for an obligatory journey. It is preferable for a husband to accompany his wife and daughters. If that is not possible and there is a necessity for them to travel to him, then there is no harm in a secure company.