I wanted to comment on your question about weight. I am an anesthesiologist and can tell you that from my perspective, being overweight is a very big deal. Being significantly overweight definitely puts a person at higher risk for having general anesthesia and for recovery from surgery. Obviously there are varying degrees of obesity, but I'll tell you what it does in general:
Obese people have decreased oxygen reserves in their lungs, meaning that after someone is under anesthesia, the anesthesiologist has to work more quickly to get a breathing tube in the trachea and has to be much more concerned about the person's oxygen level falling too fast after they are asleep.
Also, obesity often results in sleep disordered breathing. Especially concerning is obstructive sleep apnea. Does your daughter snore at night or ever seem to stop breathing or seem to struggle to breathe and then "snort"? and then wake herself up or start the whole obstructed breathing pattern again?
That type of breathing, combined with excessive amounts of fat/soft tissue in the mouth/cheeks/neck means that it could be dangerous to have her go to sleep before a breathing tube is put in her trachea. Therefore, she'd have to be sedated but somewhat awake when the tube goes in (and only THEN get to go all the way to sleep) - not impossible, but just uncomfortable.
In addition, long-standing sleep apnea issues can lead to a lot of strain on the heart, which can lead to congestive heart failure and high blood pressure in the lungs (pulmonary hypertension). Your daughter is probably too young, fortunately, to have these long-standing problems yet... but if she's significantly overweight and/or has sleep apnea, she's at risk down the road.
During surgery, providing ventilation/oxygenation to an obese patient is technically more difficult. And providing adequate pain control is tricky, too, because obese patients (and those with sleep apnea) are sensitive to narcotic medications (morphine, codeine, etc.) which can be dangerous if they cause too much respiratory depression. So titrating the right amount of medication for her operation/recovery would be more difficult.
At the conclusion of the procedure, in deciding whether or not it was safe to take the breathing tube out immediately, an anesthesiologist would have to consider the combination of: obesity, possible sleep apnea, a possibly difficult airway (which may have required an "awake intubation" at the beginning of the case), and the jaw being wired shut... This might result in the decision made for safety: keep the breathing tube in for a while (less likely to happen in the NON-obese patient) and take the patient to the ICU where they could take the tube out after the patient was more awake in a few hours or days. And, of course, it's than more difficult for an OBESE person to get off the ventilator and have their breathing tube taken out than a thinner person...
Obese patients are, in general, more at-risk for longer hospitalizations and more complications (pneumonia, etc.)
I'm not trying to scare you, although I'm sure I have (sorry!)... What I wanted to do was describe the considerations we have, as anesthesiologists, when we approach taking care of an obese patient. The best thing for your daughter would be to stress to her the importance of losing weight (even 10 pounds helps!) BEFORE the procedure. It would make her hospital course easier and less risky.
Hope that helps. Please let me know if you have any questions.