Hello @Heather179,
Go to your calendar and either hover your mouse near the left hand side of the window or click on the 4 bar icon at the top, next to the listing photo.
Then click on "Bookings".
In the window on the right scroll down to see the "House Rules" section.
Click on "yes" for the things you want to enable.
You can check out this article for information on some things that are required or advisable in a child friendly listing.
I found it by typing "child" in the "Help" section.
If I specify that my listing is safe or suitable for children, what should I know?
Some general information about charging and about guests' responsibility to say how many people in total will be staying can be found here.
Can children travel on Airbnb?
Steve.