It seems she had a complicated lap cholecystectomy
It seems post surgery she had biliary peritonitis
and that is why open surgery must have been done, and that is why t drain must have been put.
These are not normal but a known complication post lap cholecystectomy.
If the pain is too much, I would advise to get an Ultrasound
Abdomen done, to rule out any collection in abdomen.
Hope this helps. feel free to ask any more question you have.
Wishing your daughter a speedy recovery.
Dr. Rajat Gupta