Is it permissible for me to travel without a mahram to visit my sick mother and take care of my young siblings, knowing that my mother is compelled [by circumstance] and cannot provide a mahram?

If a woman has not performed the obligatory Hajj and Umrah, it is permissible for her to travel to perform them without a mahram, provided she is safe from fitnah and finds a trustworthy companionship of women only, or of women and men.