Dear Concern
rather than making her upright
start more excercises on bed in Frequency of more than 10-15 times per day of whole body with focus on spine , pelvis and limbs along with deep breathing excercises...
then gradually make her sit and with the help of proper strong back belt support make her stand in few days depending on her progress of strength...
Thanks n Regards
Next Steps
Vigorous on bed physio
Health Tips
under expert supervision to mobilise her on upright posture