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.
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.