"Many LGs do "suffer" from a "Disney" / "Fairy Tale" complex where they would like to be a "Cinderella" or "Little Mermaid" type bride.

So to an extent, they do want marriage. But I'd also say they don't know what marriage entails, or even what sex entails.

Yes - I just said it - children do not understand sex (generally).

Some children do prove they are quite capable of understanding it and how important is. Most of them do not.

This is because no one is teaching them, not at a young enough age, and never properly enough."

They observe their parents and other adults who are "married". And play house.
Do they connect this with Cinderella bride? Like, attending real life weddings of people they know as flower girls and guests?

But in many families, the parents keep sex out of sight and hearing of children, behind closed bedroom doors.

Are there many LGs who honestly would want to get married - as in, have a wedding, AND afterwards move permanently out of their parents´ household to live with her husband, do housework each day, and sleep in the same bedroom behind closed doors - without having a clue that her panties are expected to come off in her marriage bed?