She began her career as a child actor, appearing in supporting roles in Little Shop of Horrors (1986) and How I Got into College (1989) before being cast as Pamela "Pam" James on the Fox sitcom Martin, whom she portrayed from 1992 until the show ended in 1997.

She portrayed Judi Mann in the TV Land original sitcom Happily Divorced from 2011 to 2013, and from 2014 to 2017, she acted the lead role of Cassie Calloway on Survivor's Remorse.

[1] In 1986, Arnold appeared as Crystal, one of the three chorus girls who perform R&B numbers in Frank Oz's film musical Little Shop of Horrors (1986) along with future Martin co-star Tisha Campbell.

In February 1987 Arnold scored her first big break on television, with a permanent role on the soap opera Ryan's Hope.

Later that year, Arnold was cast as Sharla Valentine, a high-school friend of Emily Ann Sago (played by Liz Vassey) on the ABC-TV daytime drama All My Children.

[8] Arnold also played the voice of the friend in The Boondocks episode "Attack of the Killer Kung-Fu Wolf Bitch", which aired in 2007.

In 2009, Arnold appeared onstage in The Wiz revival at the New York City Center in the part of Evillene, The Wicked Witch of the West.

[22] The media reported that Hines had been unfaithful to Arnold, having made a sex tape with another woman during their marriage, which was later released to the public without his consent.