It is narrated from Hazrat Aisha (may Allah be pleased with her) that once I submitted in the court of the Messenger, "O Messenger of Allah! Every wife of yours has a kunyah (honorific name) except me?" The Prophet (peace and blessings be upon him) said, "Take your kunyah from your son (nephew) Abdullah." Thus, until her passing, she was called "Umm Abdullah," even though she had no children.
Hadith Referenceمسند احمد / مسند النساء / 25181
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد اختلف فيه على هشام