talk to me about putting kids in a room together

I want to put my 2.7 yo and 9 mo in the same room. my problems
1. toddler goes ot bed later - and she sings/talks to herself in bed
2. toddler wakes later than baby
3. they both nap in pm- but my toddler naps from 1-3 roughly, and baby from 2-2:30-4, roughly.
hwo do i stop them from waking each other? tell me this will be ok?