Because plastic surgery is one of the most difficult surgical matches. Even without knowing your friend we can surmise:
1) she did not apply or match into an Integrated PRS program;
2) since she did her first year and subsequent GS years at different programs, she was probably a Prelim GS resident who didn't match into a Categorical position out of medical school. This implies she was less competitive than the average GS categorical resident.
3) PRS is very competitive
4) most PRS programs, even in 2005, preferred GS residents with FULL 5+ year training rather than the 3 year (although technically meeting the requirements)
5) Hence, a low (but not impossible) chance.
Its pretty easy to look someone up:
http://www1.plasticsurgery.org/find_a_surgeon/ (presuming she is now a plastic surgeon and a member of ASPS)