The Disney princess lineup has always had some odd inclusions and exclusions. Mulan is considered a Disney princess^TM despite not actually having the title, as is Alice (some random girl), Pocahontas (chieftain’s daughter, which I guess you can argue is a similar concept), Moana (see above), Mirabel (another random girl without a position of authority), Tinker Bell, Jane Porter (although she is a noble, which is at least similar) and Megara. (From Hercules, in case you also forget that movie existed)

Likewise, the lineup does not include Nala, despite actually possessing the title explicitly. (Is Disney racist against lions or something?) Nor does it include Eilonwy, though that’s understandable considering The Black Cauldron flopped so hard it nearly tanked their animation department. It doesn’t include any acquired properties either, so as funny as it is to lump Leia into the group, officially she doesn’t count.