The Hobbit, as written, had no women in it whatsoever. As for the LOTR trilogy, as written:
Arwen: basically a prize for Aragorn and a sad footnote.
Galadriel: one of the world’s great powers, made quite an impression, gave vital gifts: certainly important, but still essentially a passive character.
Luthien: during the trilogy, just someone in a song in a scene that doesn’t contribute to character advancement or plot.
Eowyn: the exception that proves the rule, maybe.
Shelob: if you want to count her, okay. “Crucial” I’m not so sure of; import to Sam’s story arc but she was basically just a lurking danger, like the Watcher in the Water, not exactly a strong character.
If you start counting the appendices and Silmarillion, Luthien is vitally important to history and one of the world’s boldest and most heroic adventurers, and Galadriel was basically present for almost everything that ever happened on Arda and the one who really held the White Council together. But who’s reading the Silmarillion to their five year old daughter?
Anyway. The thing about this story is it was the daughter’s idea that Bilbo was a girl. She wanted someone she could project herself into. It’d be one scary kid who chose either Shelob or Galadriel for that…