The landlady owns the house that Jahy lives in in the human world.

She is ready to resort to violence in order to get her rent and unlike her sister, the store manager, the landlady is not as sympathetic to Jahy and is ready to throw Jahy on the streets at any moment. She is ready to torture Jahy and doesn't fall for her lies or bad acting. However, the landlady, fears her sister, which sometimes Jahy uses to fool her as even dropping the store manager's name causes the landlady to change personalities and become much more soft.

(Source: The Great Jahy Will Not Be Defeated! Wiki)