Yes, it did. Responsible parents don't drop off their children anywhere. Pre schoolers have their parents with them whether it is a book reading, birthday party, walking to school, or a sporting event.
When my young children went to the weekly children's movie at the library, I was standing at the back of the room with the rest of the parents. This was back in the 70's. I don't think attitudes have changed since then.
The question was why parents attend book readings? I pointed out that parents, of young children, attend all events with their children.