Early on in "The Hobbit", Tolkien briefly mentions that, before she married Bungo Baggins, Bilbo's mother Belladonna Took would go on wild adventures with her two "remarkable" sisters.
I think that would be a prequel I'd be interested in seeing.
@nickwedig I wonder if he ever wrote anything more about these adventures. This seems like the sort of thing that might have ended up in an appendix somewhere or in one of those collections of half-finished stories out there.
It might be. I don't know enough about Tolkien's more obscure works to say for sure that he didn't cover those adventures somewhere.
But I doubt it. Tolkien wasn't very good about remembering to give female characters any agency... Or even remembering to have female characters at all.