In grade-school, the girls always had their chapel veils on before we entered the Church. If you forgot yours, you had to use a paper towel and pin it to top of your head.
Back in Catholic school we always put them on before we went into the church. We put them on in the classroom so if someone didn’t have theirs the teachers/nuns would know right away and they’d have to wear a hankie on their heads.
Remember the little round doilies you also could wear? They came in black or white and were held on top of the head with a stick pin or bobby pin.