The four-time Olympic gold medalist then replied: "I'm done with themes! No more themes."
The "Texican" stunner - who relies on stylist Charlene E. Roxborough Konsker - rocked a red bandanna ponytail with matching belted halter dress and white Converse.
Meanwhile, the 5ft9in athlete's older sister Venus looked ready for church in her red hat, matching kitten heels, and b&w-dotted dress.
And 31-year-old Ciara managed to flaunt substantial cleavage despite her long-sleeved white blouse tucked into a grey skirt and white sneakers.
36-year-old Kelly (born Kelendria) checked her cherry red lipstick in the mirror of the crimson car in a b&w-patterned crop-top, white skirt, and black sandals.
The five-time Grammy winner tied back her curly raven bob with a printed head scarf while pretending to look under the vehicle's hood.
The former Destiny's Child singer also took a selfie with 38-year-old La La, who wore a blue bandanna in her hair and a b&w-gingham button-up for the shower.
Williams is expecting her first child with her fiancé of eight months, Reddit co-founder Alexis Ohanian.
"Obviously, [Serena] won the Australian Open while pregnant [in January] and she remarked that she feels like it has to be a little girl," the 34-year-old internet entrepreneur said on Wednesday's Jimmy Kimmel Live!
"Because everything that little baby went through and handled like a champ, only a woman could be strong enough to take on."
