Propagating succulents is such a great way to get new plants! And you’ve already done the hard part: getting your leaves to produce rosettes!
Once you start to see roots, cover them with soil. This way they will stay cool and have access to water. Keep watering so that the soil stays damp.
You don’t need to do anything with the mother leaf. As the baby succulent gets larger, the mother leaf will begin to shrivel up and die. This is totally normal, and the mother leaf will fall off and separate from the baby leaf on its own.
Once this happens, continue to provide plenty of water for the baby succulent. Then, once it is well rooted and growing well on it’s own you can move it to another pot or place it in another arrangement.