Is it permissible for a woman to travel alone with her young child?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: A man residing in these lands, from the people of Yemen, is very poor and cannot find enough to sustain himself and his family. He wants to send his wife to Yemen by bus, and her only companion is her young son, because he cannot afford the fare for both of them. What is the ruling on this?

Answer:
The default ruling is that it is not permissible for a woman to travel without a mahram (a relative one may not marry). The Messenger (peace and blessings be upon him) said: She should stay with him until he is able to travel with her. She should stay with him until he is able to travel with her and take her to her destination. So she must not travel without a mahram. Yes.