The E! Fashion Police star hosted the Miss USA Competition in Las Vegas, Nevada on Sunday night (June 3).
The 27-year-old is currently dating vegan chef Matthew Mosshart, who she met last summer at Kate Moss's wedding to Jamie Hince.
She previously revealed that she caught "baby fever" after her brother Jack Osbourne welcomed his first child with Lisa Stelly.
"I've got baby fever after I saw [her]," she shared. "I'd be the best mum ever. I would. I've got great training from my mum."
Osbourne said that it was "love at first sight" when she met her baby niece, describing her birth as "the most amazing thing that has ever happened" to her family.
Watch a clip of Kelly Osbourne on Anderson below: