Hello and welcome to HCM
Yes if the air bubble below the rib increases than surely she needs an emergency surgery. As it is not clearly written by you whether air is present under Diaphragm or in chest. If it is under diaphragm than it indicates perforation of intestine otherwise it is a chest injury
which include lungs.
In both the cases If it does not resolve needs surgery.
Dr. Dinesh Kumar Bhatia
Health Care Magic