I like the suggestion of Cadence -Cady is a cute nn!
Teagan is my fav from your list. Have you thought of Tinley?
Here are some ideas based on your ideas. Mason, Beau, and..
Love some of your choices...how about the following:
From your list I like Auden and Avery.
I don't think that Lilyan is cowgirl material.
Adabelle (from the beautiful scenery)
Anna (gracious, merciful)
Ashton (from the east town)
Audie (means of noble strength)
Georgia (farming woman)
Haley (meadow of hay)
Hillary (cheery, humorous)
Ida (hardworking woman)
Jana (God is merciful)
Josephine (God raises)
Justine (Fair, rightful)
Kasey (Alert, watchful)
Lilibeth (promise of God)
Maxine (the greatest)
Shannon (wise woman)
Victoria (woman of victory)
Willow Grace gets my vote.
From your list I like Willow. Such a pretty name! I don't like Cassidy because of its associations with Butch Cassidy (outlaw). I think if you're going for cowgirl you can't escape that association.
Hmmm...yes, regarding a cowgirl, Lilyan Mae is pretty (though I agree on the preferred spelling: Lillian Mae).
Hmmm...:) what about also these options: