GOING THE DISTANCE Following in her father's footsteps, Vanessa Kerry is training to run in the Boston Marathon. John Kerry's youngest daughter is studying in London on a Fulbright scholarship, but told friends in a recent e-mail that she's training for the April race. (Her father has said he competed in the late 1970s.) In the e-mail, Kerry said she's running as part of the Dana-Farber Cancer Institute's marathon team and invited friends to visit the Dana-Farber website and make a donation supporting cancer research. (Among those who've responded are famous friends: singer Carole King and Al Gore's middle daughter,...