Some of the most well balanced information and evidence out there regarding u/s size estimates, induction, unnecessary c/s and INFORMED CONSENT is on that site.
that dr is full of crap and not making recommendations according to medical evidence, nor with regard to your friend's bests interests, let alone the practice guidelines set out by ACOG. ACOG says c/s for "big baby" is not recommended. as stated above late term u/s are NOTORIOUSLY wrong for size estimates.
the nursingbirth blog (just google "nursingbirth") has a "don't let this happen to you" section that covers inductions for "big babies"
All birth has risks. It's a matter of weighing the risks v. benefits. The danger to her of a c/s or unnecessary early induction (that will likely head to c/s) to try to avoid having a big baby is huge v. the risks of a vaginal birth.
it's also fairly common for the bladder to be nicked during surgery - requiring another surgery to fix that damage. Risk of infection, fetal injury - yes babies sometimes get get during c/s. blood loss requiring transfusion for the mother... anesthesia complications... death.
the risks to her future fertility b/c of an unnecessary c/s are important to consider. The recovery time is significantly longer. And frankly it's no fun trying to take care of your first child when you can barely stand up straight or pick up the new baby for weeks.
My last baby 10.5# and I am an average sized person. That baby was my VBA2C baby and was a full pound larger and had a 2cm larger head than my first c/s baby. I've met petite women that have given birth vaginally to similarly sized babies.
your friend has already had a vaginal birth. there is no reason for her not to go into labor on her own. Her pelvis already knows what to do.