In a sweet video, which was shared by her fiance Matthew Koma, the family could be seen watching 'The Lizzie McGuire Movie' together on Sunday.
"Family viewing of Lizzie McGuire movie," Koma captioned the video shared on his Instagram story, which Duff later reposted on her own Instagram Story.
In the clip, Duff can be seen laughing while her two children, 7-year-old son Luca and 11-month-old daughter Banks, stare at the screen watching their mother sing 'The Tide Is High' in the movie's opening scene.
Koma can be heard saying jokingly, "Yup" in the background while Duff sings "every girl wants you to be her man," in the popular 2003 movie.
The family's party follows Duff's birthday celebrations. The actor turned 32 on Saturday and her beau threw her a jungle-themed birthday party, complete with a live monkey.
"I asked to meet a monkey for my 32 birthday and of course [Matthew Koma] made my dreams come true," Duff shared on her Instagram Story, along with a photo of the monkey climbing on her shoulder.
In August, Duff announced that she would be reprising her character in an upcoming revival, and said that it earned her some points in the "cool mom" category with her son.
"I recently started talking to him about Lizzie McGuire and showing little clips on YouTube. I think he's pretty fascinated to see me so young, not looking the same, but obviously he knows that's his mom," she told People at D23 last month.
"I think that he thinks I'm cool now, which is awesome. I'll take that for as long as I can have it," she added.
The original series, which ran from 2001 to 2004, followed 13-year-old girl called Lizzie McGuire, who dreamt of being popular in school, as her animated alter ego represented her true feelings. The show was later made into the film, 'The Lizzie McGuire Movie', where Lizzie went on a trip of a lifetime to Rome, Italy, following her 8th-grade graduation and got mistaken for a pop star.
The upcoming revival will follow Lizzie as a 30-year-old who works as an apprentice to a fancy New York City decorator.
Speaking to People after the announcement, Duff said she felt like it was "the right time" for the show to come back.
"I think it's the right time to set back in and have her go along with you in your 30s and all the fun times, and all of the big monumental moments, and all of the challenges that you're faced with," she said.
'The Lizzie McGuire' reboot will air on Disney+, which launches on November 12. (ANI)