My guess is:
Julia Holter - Have You in My Wilderness.
It’s definitely the most pop-sounding album Julia Holter has recorded!
Cheap vinyl availability - check
1. Female Artist
2. Not one of Teeee's top 5 pop albums of the decade (at least the list of them I’ve seen)
3. Post November 1964 (Ronettes album)
4. Artist born in USA
5. Artist has never performed with Beyoncé
6. Artist's 4th album (not counting EPS)
7. Genre is pop-rock/pop-singer/songwriter, not just "straight up singer songwriter". Not a choreographer. Not stereotypical pop.
8. Artist did not perform at Lilith Fair
9. gouis (who doesn't like pop much) would/might/does like the album
10. Album is from this decade (2010)
11. (GIF clue referred to as Jekyll and Hyde): ?
12. She’s still alive
13. As above, the EPS weren’t counted
14. Don’t know about JQBX
15. I interpret that gif clue to possibly be about sleepwalking and she has a song called “Night Song"
Those are my quick takes. Welcome to the party
@NathanRicaud !!