There were two, in 1930:
Mme Marguerite Mareuse, and Mme Odette Siko. I think Mme Mareuse started the race - it was her own car!
They shared a Bugatti T40, and came 7th, covering 2607.661 km, against the winning Barnato/Kidston Bently Speed Six ("Old Nunber One)'s 2930.663km.