This pretty, sharp-featured actress made a niche for herself playing funny, smart-mouthed character roles on TV and the big screen. A Chicago native, Dunn studied to be an artist before moving to California. By 1981, she was working as a stand-up comic. Dunn joined her hometown's Roxy cabaret in 1983 and moved East when she was cast in "Saturday Night Live" (NBC) in 1985. Her five year stint on the venerable sketch comedy show was relatively uneventful with her only memorable characters being obtuse talk show host Pat Stevens and one-half of the Vegas-style Sweeney Sisters act. In 1990, Dunn