As far as I have read, she was one of two women sent by the Mawqaqas of Egypt to the Prophet. The Egyptian monarch had received the Prophet's letter inviting him to Islam and although he himself never became Muslim, he responded warmly to the letter and replied he had thought the Prophet was going to be from Syria. The Egyptian king was a Coptic Christian as were his subjects and so were the two female servants he sent, Mariya Qibtiya and her sister, whose name I believe was Serena. Mariya, as mentioned entered the Prophet's household and after his death became a recluse. She would visit both the Prophet's grave and her son Ibrahim.