How would Rapunzel cover her hair after getting married, assuming she's Jewish?
She should get a Thneed- it's a fine something that all people need! They're durable and versatile and can easily be made into a giant head covering.
Snoods are amazing - at least this is what almost every one of my female married friends tell me. (My wife disagrees, but, there's a separate reason for that.)
Snoods are flexible, durable and, best of all, extandable and sizeable. I would imagine that Rapunzel's snood would probably have to be the size of a huge trash bag, but, so what? Best of all, as Rapunzel's hair grows longer, it is easy to stretch the snood or just add more yarn / fabric to make it bigger.