The author of one of Britains most popular baby-care books is suing a parenting Web site for defamation. Gina Ford is the author of The Contented Little Baby Book, which advocates strict routines and letting babies cry themselves to sleep. Shes long been a target for criticism; one TV magazine did a segment called Gina Ford: Who Are You to Tell Us? (Ford has no children herself). Now shes suing the Mumsnet Web site, saying that derogatory member postings on the sitesuch as one calling her a fart-faced, rolly-fluff poodo not constitute fair comment. Mumsnet founder Justine Roberts, a mother of four, has banned any mention of Ford from her site until the suit is settled. Holding a sites owner responsible for defamatory comments would be unprecedented in Britain.