I’d go EF also . I love the Isabella quarter especially that it was made for the Worlds Fair in Chicago by a prominent lady Mrs Palmer was wife of Thomas Palmer of Palmer house fame . She was one of the richest ladies in Chicago .
I also am very fond of the Isabella. But I have to be the contrarian on the grade of this coin as visible from the photos. I think it's not better than about VF-30 because there is so much design detail lost from the coin. Compare the submitted coin to this one in MS-64. Note the dress, necklace, hair, cofia and crown detail worn down or lost due to wear. On the reverse, most of the detail in distaff, hair and coveralls are lost due to wear. As a circulated coin, it's a nice item but I don't think it's an XF much less an AU.