The reality show will launch on Channel 5 later this summer with a four-week run featuring famous faces living in the iconic house.
The Daily Star reports that the former S Club 7 star was targeted by bosses to bring "the sex factor" to the series.
"Rachel is on our hitlist," a source told the paper. "She still oozes sex appeal."
Stevens, who finished second in Strictly Come Dancing in 2008, was previously engaged to former Celebrity Big Brother housemate Jeremy Edwards.
The 33-year-old and her husband Alex Bourne became parents to daughter Amelie last November.
Details of open auditions for the non-celebrity version of Big Brother, which will follow the all-star series in September, were revealed yesterday.
> Take a look at our full Big Brother coverage