how long does it take for a female emperor scorpion to become an adult or to be able to breed?

It takes a variation of time depending on the environment and such, which humidity is a key factor in triggering molts (And temperature somewhat...) an adult female emperor will only breed or give birth in optimal conditions which are around 75-85% Humidity and 80-90 Fahrenheit with 4-5 inches of soil, or something they're able to burrow in (I use eco-earth), if the scorpion has not become an adult yet, humidity can trigger their molting somewhat, if you do however get a brood of baby scorpion make sure to give the mother crickets without their back legs, she'll take care of the babies, if you want to keep them in the tank with the mother after they leave her back, make sure the mother's well fed, or she will cannibalize the young, but really, their conditions need to be optimal before breeding/giving birth, good luck.