The trio will share an Oreca 07-Gibson run by regular LMP2 squad Signatech under the 'Richard Mille Racing' banner, with support from the FIA Women in Motorsport Commission.
An entry for Le Mans has been submitted by the new outfit, and should it be selected, the team would field the first all-female line-up in the French enduro's prototype ranks since 1991, when Lyn St. James, Desire Wilson and Cathy Muller shared a Spice SE90C.
It would also mark a first Le Mans appearance for all three drivers.
While ex-IndyCar and DTM driver Legge is an established endurance racer in the IMSA WeatherTech SportsCar Championship, her teammates Calderon and Floersch will both be embarking on their first full seasons in sportscars.
Calderon made her debut in the discipline in last month's Rolex 24 at Daytona, sharing a GEAR Racing-run Lamborghini Huracan GT3 Evo with Legge, Christina Nielsen and Rahel Frey.
The Colombian, who raced in Formula 2 last year, is expected to miss the Barcelona ELMS opener owing to a clash with her Super Formula programme with Drago Corse.
Sophia Flörsch, HWA Racelab