The 'Real Housewives of Beverley Hills' star - who has two children, Mason, nine, and six-year-old son Jude, with the 'Frasier' actor - explained even though her former spouse is now married to Kayte Walsh, there is "so much paperwork" involved with changing her moniker.
She said: "Our children are Grammers and it's easier to keep the Grammer last name because of them.
"There's so much paperwork that goes with changing a name. We're still going through a custody battle ... it's just easier."
Camille also admitted she now thinks fiercely "private" Kelsey encouraged her to take up a role on 'Real Housewives of Beverley Hills' so she was kept busy in Los Angeles, while he entertained former flight attendant Kayte in New York.
She added in an interview with chat show host Wendy Williams: "I couldn't understand why he would want me to be on the 'Housewives', because we were always such a private couple - it was to keep me preoccupied in Los Angeles so he could have his affair in New York."
Camille - who was married to Kelsey for 14 years - has previously admitted she still wears a diamond ring the star gave her as a fifth wedding anniversary gift.
She said: "Would you buy a woman you didn't love this ring? He loved me, no matter what he says!"