Quick question for mamas who have cloth diapered !!

MaKayla • 21• Married to my Middle school Sweetheart! • PCOS • due with #1 on 07/01/2020

I am due July 1st (so we are getting there! ) :) anyways my cousin cloth diapered all 3 of her girls and that’s how I learned about it ,, I LOVE it and my husband and I have decided we are doing it no doubt.... I am getting ready to spend some money and get some diapers so we are ready.... will 40

Diapers be plenty or should we get a bit more ? Also ,, will she be able to use them up until she’s done with diapers ?? TIA xx