Is a mother considered disobedient to her mother if she travels to work abroad without her mother's consent, knowing that she is in urgent need of travel to cover the expenses of her children's university education, and that she is 48 years old?

If your travel would cause your mother, who needs you, to be neglected, then it is not permissible for you to travel or to disobey her; otherwise, you would be disobedient. However, if your travel would not neglect her and you are in need of it, then you are not sinful for it, provided the travel is permissible شرعًا (Islamically). Scholars have stated the permissibility of a child traveling to seek necessary sustenance without the permission of their parents. The advice in all circumstances is to obey your mother and stay with her, for honoring her is among the dearest deeds to Allah and the quickest in reward, and the most blessed in sustenance and lifespan. Ibn Abbas said, "I know of no deed closer to Allah عز وجل (the Mighty and Majestic) than honoring one's mother."