After about a month alone it should have changed to a female so after 1 1/2 yrs she is definately female ... best bet is a juvenile as it will at worst be just sexless at that point and when introduced to your turn male ... dont be alarmed if the female chases it around for awhile ... things will settle down once he figures out who is the boss
Dont think it much matters whether tank raised or wild caught ?
Good Luck
Cheers