An attractive ingenue who invited comparisons with Elizabeth Taylor when she put a "modern woman" spin on Taylor's famous role in the 1991 remake of the 1950 sentimental comedy "Father of the Bride", Williams began acting in commercials as a teenager and got her first TV role as the Other Woman in "Stood Up" (1990), an "ABC Afterschool Special".

Williams was attending Northwestern University when she won the role of the daughter of Steve Martin and Diane Keaton in "Father of the Bride". She gained favorable notices for her wholesome, no-nonsense approach to the role. She returned to college, appearing only in such low-impact fare as the thriller "Secret Games" (1992) and the comedy "Indian Summer" (1993). Williams reprised her role as Annie Banks, this time as an expectant mother, in "Father of the Bride, Part II" (1994), loosely based on "Father's Little Dividend" (1951). In 1996, she appeared in "The War at Home" before making her TV series debut on ABC's romantic drama "Relativity" (1996-97).