She is best known for her leading role as teen witch Marnie Cromwell in the Halloweentown film series (1998–2004), co-starring Debbie Reynolds.

Brown first gained recognition for her portrayal of Marah Lewis in the CBS soap opera Guiding Light (1993–1998, 2006), which earned her a nomination for the Daytime Emmy Award for Outstanding Younger Actress in a Drama Series.

In the movie, she played 13-year-old Marnie Piper, a young witch who is determined to learn magic from her grandmother Aggie, portrayed by Debbie Reynolds.

[9] Halloweentown aired on October 17, 1998 and was well received by audiences, leading Disney Channel to produce three sequels; Brown reprised her role as Marnie in two of them.

[24] In 2016, she reconnected with Halloweentown II co-star Daniel Kountz for a Halloweentown-themed project for Brown's YouTube channel, and they soon began dating.