Cervical cancer in 15-19 year old girls occurs in 1 in every million girls. A good gyn won't do a pap on her.
Ovarian cancer is nearly impossible to detect by bimanual exam and only occurs in 4 of every 100,000 women below the age of twenty (those pretty much all have a genetic syndrome that leads to it)
Breast cancer rate is 0 for every 100,000 at her age.
Unless she has reason to think she has an STD, a visit to the gyn will entail an unneeded pelvic exam followed by an unneeded breast exam. The only real reason to go is if she needs/wants Rx birth control.
I'm a female physician. ACOG guidelines are set to cater to the lowest common denominator (people who NEED to be tested for STDs) and to make your gyn money. Just think how quiet their offices would be if all of us stopped traipsing in there once a year to be examined...