Generally, most carpets will attain sexual maturity anywhere from 2-4 years, although I have heard of it being reached as early as 18 months in males.

You will want to ensure that your female is up to an appropriate body weight/condition prior to breeding, generally around ~1500 grams at minimum. Clutch sizes, fertility, and overall reproductive health of the female are all implications to consider should you decide to breed them at earlier ages.