[2] The plot follows a teenage girl (Draper), who discovers that her mother's fiance (Guest) and her own future stepsister (Hope),[3] are actually strange aliens from another planet hiding out on Earth.

[7] Michael Speier of Variety commended Draper’s portrayal as the film’s most compelling element and suggested it could attract attention from casting directors seeking more substantial talent.

Speier found the film effective in conveying themes of interplanetary camaraderie and praised the performances of Tamara Hope, Khrystyne Haje, and Lance Guest, despite some issues with American accents from local actors.

[8] Jessica Rawden of CinemaBlend observed that, among the various unconventional Disney Channel original movies, Stepsister from Planet Weird remains a personal favorite from 2000.

[10] Tom Cassidy of Common Sense Media gave the film a score of 4 out of 5 stars and said that Stepsister from Planet Weird is a heartfelt Disney TV movie that addresses complex themes such as divorce, the death of a parent, and blending families.

Cassidy praised the movie for its effective exploration of these issues through the experiences of its likable leads, Megan and Ariel, noting that it teaches empathy and understanding while maintaining consistent humor.

Cassidy also mentioned minor concerns, such as a potentially frightening ray-gun scene and mild language, but emphasized the film's overall warmth and responsible portrayal of adult-child relationships.

[11] In 2017, CableTV.com analyzed the entire catalog of Disney Channel Original Movies (over 100 films) and utilized Google Trends data to determine the most popular DCOM in each state.