My 4 yr old makes the sign of the Cross, says Grace at meals, knows the Our Father, and can recite the HAil Mary along with me when we do the Rosary (but she’s too self-conscious still to try saying it on her own).
My 2 yr old has finally gotten the Sign of the Cross down LOL . He can say Grace before meals and can repeat after his sister with the other prayers, but he doesn’t have them “down pat” yet.
Being consistent with them really helped, plus my daughter has a phenomenal memory. Surprises even me!!! I don’t think I knew the Our Father until I was 7!