Arya used to be my favorite character, but after the way she lashed out at Yara, I don't fancy her as much.

Yara is Queen of the Iron Islands and Arya is a glorified Assassin, she did Kill the Night King and save everyone I guess though, but she would never would have had the chance if Daenerys did not put everything on hold and bring her armies and dragons to Winterfell. And Arya did not even respect Dany for that, the moment the battle was over her and her sister Sansa started scheming against her--why? Because they did not like there brother's girlfriend essentially. When Dany died, and Arya turned into a bitch with her sister, everything changed. An Arya spinoff just would not work, her character has nothing to offer anymore, her arc is over. Love Maise Williams though, but I think I like Emilia Clarke and Gemma Whelan just as much, if not more now.