Rreshma Saujani, a Wall Street executive and lawyer who’s ru mored to be prepar ing a challenge to Upper East Side Rep. Carolyn Ma loney, was round ing up supporters at the party Ce lerie Kemble and her friends Bronson Van Wyck and Mariska Hargitay threw the other night for WomensLaw, a domestic violence Web site run by Kemble’s sister-in-law, Elizabeth Martin. Gloria Gaynor and Moby had the crowd cheering, but Saujani, who was once a White House intern with Monica Lewinsky and raised big bucks for John Kerry‘s presidential campaign, kept discreetly off the Skyline Studios dance floor.