U.S. Rep. Sheila Jackson Lee said today she does not know the woman who falsely claimed to be a physician when she made a statement supporting the White House's health care overhaul at the congresswoman's town hall meeting Tuesday. The woman, a University of Houston student named Roxana Mayer, is not a licensed physician, although she called herself one at the meeting and was incorrectly identified as such in Wednesday's editions of the Chronicle. In an e-mail to the Chronicle today, Mayer said she'd been advised not to talk further about the matter, but did not say who counseled her....