I only remember Mara Branković, daughter of Đurađ Branković, and step-mother of the famous Mehmed the Conqueror. She married his dad Murad II, which helped Serbian and Ottoman relations, but he died and war did broke out and she left, living in the Empire but somewhere, in the Greek islands (part of the Empire), the war resulted in Ottoman victory and annexation of Serbia. I also find it weird she refused to marry the Byzantine Emperor you know a Greek man, with similar faith, but chose to marry Murad II (who by the way has a Greek great-great-grandmother and a Greek great-great-great-grandmother).

Anyway she lived in the islands, being a step-mother to a boy who became a Sultan (whose real mother died, and he used to call Mara mother), and also witnessed her step-grandson go be the next Sultan.