For those keeping score, it's Laura Ingalls, 2, and Rhoda Morgenstern, 0. Former Little House on the Prairie child star Melissa Gilbert trounced onetime Rhoda star Valerie Harper in a rerun of last November's voided Screen Actors Guild presidential election. According to results made public Saturday, Gilbert won 57 percent of the vote to Harper's 34. At last night's world premiere of Ice Age at New York's Radio City Music Hall, star Ray Romano, on hearing of Gilbert's triumph, joked to TV Guide Online: "Tell her I won't take any more non-union work."