julie krone came back for a little bit after retiring ? no ?
http://en.wikipedia.org/wiki/Julie_Krone
and Rosie Homeister is back riding too now.
Rosie left the door open;
http://en.wikipedia.org/wiki/Rosie_Napravnik
After her win in the 2014 Breeders' Cup Distaff, Napravnik announced she was seven weeks pregnant and taking a "retirement" of "indefinite" duration from race riding following the 2014 Breeders' Cup