I disagree.
Chelsea looks a bit like Webb, a bit like Hillary, nothing at all like Bill. But Webb's looks aren't all that distinctive. Neither are Hillary's. The teeth tell the story. Neither Webb nor Hillary have teeth like that.
Jimmy Carter has teeth like that. He had an illegitimate daughter by an unknown woman who looks a bit like Webb and a bit like Hillary. The south abounds with such people. Other white southerners uncharitably call such people "trash".
Carter paid off the mother and got rid of an embarrassment. To Carter's credit, no abortion. Bill and Hillary got a show-child and quite a bit of behind-the-scenes political pull. Deal made.
Eleanor Roosevelt had teeth like that. She had an illegitimate son by Joe Kennedy. Legally she could have passed him off as Franklin's, but Franklin was with Uncle Joe at Yalta (or was it Teheran) during the appropriate time frame. Franklin would have known it was not his.
Carter's putative mother Miz Lillian was just a decent southern lady who'd just had a miscarriage that left her sterile. Joe Kennedy found her. She wanted a baby. Deal made. Sworn to secrecy, of course. The only decent human being in this sordid family saga.
Joe Kennedy's legitimate sons have looks that take after their mother Rose, a beautiful woman. John-John inherited those looks.
Chelsea Roosevelt Kennedy Carter inherited Eleanor Roosevelt's teeth, but the Vanity Fair folks compare her to her cousin John-John. They know the score.