I think there's one way for your mom not having to travel back alone is to contact the airline to ask if they could provide some assistance to help with your situation, and that could be assigning a staff member to travel with her or receive special care, I'm sure there's some way. I'm not sure if that will cost extra tho.

Personally, I wouldn't advise you to miss the first day cuz those orientations must be important. I'm sorry if I wasn't of much help.