Answer
The mother of Manuel II Palaiologos was Helena Kantakouzene. She was the daughter of John VI Kantakouzenos, the Byzantine Emperor, and Maria Asanina. She was married to Andronikos II Palaiologos, the Byzantine Emperor, and they had four children together, including Manuel II Palaiologos. Helena Kantakouzene was a powerful figure in the Byzantine Empire, and she was instrumental in helping her son, Manuel II Palaiologos, become Emperor.