United accidentally gave a toddler's seat away - and made his mom hold him for a 3-hour flight

United Airlines has apologized to a passenger who was forced to give up her 2-year-old son's seat and hold the child on a flight - until her leg and arm went numb.

Shirley Yamauchi, a middle school teacher from Hawaii, was bound for a teacher's conference in Boston last week, she told Hawaii News Now. Her traveling companion was 27-month-old Taizo, whose…