She appeared on the first season of the Italian version of The Mole (2004) and on the third season of the VH1 reality show The Surreal Life (2004). In the show, Nielsen was seen flirting with Public Enemy rapper Flavor Flav and it was confirmed that they were a couple, even though she was still legally married to Raoul Meyer. The show was such a success that VH1 produced a spin-off reality show called Strange Love, which began airing on the channel on January 9, 2005. Nielsen also appeared with Flav on VH1's Big in '04 Awards. In 2006, she guest-starred on Flav's other reality show, Flavor of Love.

In 2004, Nielsen appeared in the Danish Big Brother VIP, one year later in January 2005 she was also a contestant in the British equivalent Celebrity Big Brother along with her former mother-in-law Jackie Stallone and the writer Germaine Greer, Nielsen eventually coming third in the final public vote. In 2006 she appeared in another reality TV series, VH1's The Surreal Life: Fame Ga