Firstly I've never had anything mentioned about not looking after your child during working hours in any contract for any job I've ever had😂
Not sure why that is funny.
There are an abundance of things not explicitly written in my contract, because it is just obvious.
No, it doesn't say "You have to have childcare in place for your working hours" because it is obvious, and doesn't need to be stated.
Mine doesn't state "You need to be clothed whilst on zoom / Team / any other meeting" because it is just damned obvious to any sane person. Mine doesn't state "You mustn't tell the clients / customers / service users to F* Off" either, because, once again, it is just implied, that normal sane people don't do that whilst they are working.