@14pokies hahaha. Oh jeez. I gotta just wait for a larger, decent molt. I'm impatient though and now I'm torn. I wanted a male, but after this last molt it's growing on me a little. I'm starting to actually *gulp* LIKE it. Dang it.
@CyclingSam The breeder told me I should be able to tell with this next molt. It was destroyed, so.... No go. But a wise woman (aka @VanessaS) once told me to wait until they are AT LEAST three inches. And even larger to be more sure. I guess I will wait!!!!
It has been my experience that an average sized species, approximately 5-7" as an adult, has very easily spotted spermathecae at the 3" mark. I've had a number of individuals who I thought were male, up to the moult that they reached 3", and then spermathecae was very obvious once they reached 3".
Of course, smaller individuals will be obvious at smaller sizes. I saw my Euathlus parvulus female's spermathecae at about 1".