All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
It is not permissible for you to travel except with your husband or your Mahram (a non-marriageable man). The Prophet said: "A woman should not travel except with a Mahram." [Al-Bukhari] But if you have a son who has reached the age of puberty, then there is no harm on you to travel with him, Inshaa' Allaah. It is also permissible for you to travel with your non-Muslim brother according to the most preponderant opinion of the scholars, if he is an adult sane person and if you feel secure by travelling with him. It is permissible as well for your young daughter who has not yet reached the age of puberty to travel with safe company, if she is young and she is not sexually desired at her age. As regards the travel of a young son at the age stated, it is not permissible to let him travel on his own as he is exposed to danger, but if there is safe company, then it is permissible to let him travel with them.
Allaah knows best.