According to the EGW, by the battle of Yavin, clones shrank to about a third of the overall Stormtrooper Corps, Also I just realized the women (it presents her through her "memoirs") is quoted at 33 ABY, about three decades after Endor. But I found this on Wookieepedia, : "George Lucas, when composing background information for licensees in 1977, stated that females did exist in the Stormtrooper Corps, although there were few stationed on the Death Star. He suggested that they were numerous in other units. As a result, few female stormtroopers are depicted in Expanded Universe sources."
The more you know!