Hm. For some reason, that's an issue that wasn't raised in the cases of Hillary Clinton (except for Michelle Obama questioning her capacity to "run The White House" when she "couldn't run her own house") or Michigan Democrat, U.S. Senator Debbie Stabenow -- or even most of the Kennedy family.
As for Bristol Palin's pregnancy somehow reflecting a failure of "abstinence education" -- well, the idea that someone got pregnant because they were taught that premarital sex is wrong is ridiculous. (As is the idea that any young person in this day and age doesn't know what birth control is, or how to buy it in any drugstore in America.)
Young women throughout history have found themselves in Bristol Palin's position -- but they found themselves there much less frequently before there was an entire industry dedicated to assuring young people that having sex even at young ages is "no problem," so long as they don't get pregnant.