SUZY.

Nancy Reagan is in town from California, looking as pretty as her Aaron Shickler portrait hanging in the White House, and that's some pretty. Nancy was dressed all in brown from top to toe at Carroll Petrie's little late lunch for her at the Carlyle, complete with such members of Nancy's fan club as Hilary and Joe Califano and Bob Colacello, who wrote that fine story on the Reagans for Vanity Fair. At Louise and Henry Grunwald's little dinner for Nancy at their beautiful flat on Park Ave., Nancy wore a sensational jacket embroidered a la Matisse in brilliant paillettes designed by Bill Blass, who was there to see her in it. Last night, Carolina and Reinaldo Herrera gave another little dinner in Nancy's honor at their glorious townhouse. Again, Nancy stole the show, but more of all this next week. Although Nancy loves seeing her New York friends and …