Not even that.
Hilton was housed in the "special needs" unit of the 13-year-old jail, separate from most of its 2,200 inmates. The unit contains 12 two-person cells reserved for police officers, public officials, celebrities and other high-profile inmates. She didn't have a cellmate
That's a form of "preferential treatment" I honestly don't have a problem with. Having a high profile inmate in the general population, a high-profile target, puts not just the target but the staff at risk. As long as the physical conditions, diet etc. are comparable in the isolation unit. Not giving her a cellmate, I'm not so certain about.
But even if she were in gen pop, i think she'd have been pretty physically safe. And probably in better shape psychologically, because she lives on attention.