Family
- mother Pauline MacDowell: divorced MacDowell's father c. 1964; struggled with alcoholism and died of a heart attack when MacDowell was 23 (c. 1981)
- father Marion MacDowall: retired; walked out on the family when MacDowell was six (c. 1964); remarried
- sister Babs Rogers Richard: older
- sister Beverly MacDowell: older
- sister Julia MacDowell: older
- half-brother : younger
- son Justin Qualley: born c. 1986; father, Paul Qualley
- daughter Rainey Qualley: born in March 1989; father, Paul Qualley
- daughter Sarah Margaret Qualley: born c. 1995; father, Paul Qualley
Companions
- Dennis Quaid: were reportedly involved when they were shooting the HBO film "Dinner With Friends"
- Olivier Chandon: linked romantically with the champagne heir during the early 1980s
- husband Rhett Hartzog: born c. 1958; from Atlanta, Georgia; had attended high school together in Gaffney, South Carolina; became engaged in July 2001; married on November 10, 2001
- Companion Kevin Geagan: engaged January 2006; married twice before; has three daughters from his previous marriages
