HBO sent out an official release and, given the deaths of both Fisher and Reynolds this week, the film's air date has been moved up.
"The story of a family’s complicated love, this documentary is an intimate portrait of Hollywood royalty in all its eccentricity," an official release from HBO stated today.
The doc will include everyday details about the two living next door to one another and Fisher's concerns over her mother's continuing to perform well into her 80s.
"Carrie’s response is both hilarious and heart-rending. Featuring vintage family films that bring iconic old-world Hollywood to life, as well as extensive vérité footage, the film is directed by Alexis Bloom and Fisher Stevens," the release adds.
Fisher died on Tuesday at the age of 60, days after she went into cardiac arrest. The next day, Reynolds died after suffering a stroke, her son Todd Fisher told ABC News earlier this week.
"Bright Lights: Starring Carrie Fisher and Debbie Reynolds" airs Jan. 7 at 9 p.m. EST on HBO.