Jennifer Westfeldt earned a place in the pantheon of spunky New York heroines as the charmingly neurotic title character in ''Kissing Jessica Stein,'' the 2002 indie hit she wrote with Heather Juergensen. Now she's playing a striving newcomer from a more innocent era, Ohio native Eileen Sherwood, in the 50th-anniversary revival of ''Wonderful Town.'' ''The show is set in the '30s, but the themes are timeless -- coming to New York to fulfill your dreams and dealing with sublets, crazy neighbors, and random jobs,'' says Westfeldt, 32, who spent her first few years out of Yale toiling in Off Broadway obscurity before landing on TV shows like ''Judging Amy.'' '''Wonderful Town' is a love letter to New York, not unlike my film, and both center on the relationship between two women.'' (Donna Murphy costars as big sister Ruth.) Though Jessica Stein sang a few bars at a Sabbath service, Westfeldt hasn't done a musical for years and cheerfully admits being ''panicked'' about Broadway critics. ''As an actor, you can make many valid choices, but as a singer, you hit the note or you don't -- and that's scary.''