You do not have a link list with a handle set to infant, or you do and it's empty. Go ahead and create a link list called Infant on your Navigation page and populate that link list with links that point to collections, to see collections listed here. Make sure the link list also has a handle set to infant.
The perfect onesie's for the new tiny love of your life. Let them wear something adorable in the most comfortable onesie they own.