Legend has it that as a girl abandoned by her mother, she followed her father Eugene to the monastery under the name Marinos by dressing up as a boy. She lived as a monk — no one recognized her true gender — until one day a woman accused her of being the father of her illegitimate child. Marina was expelled from the monastery and now took care of her child in front of the monastery walls. Only after her death did the truth come out.
There is a Sicilian legend about Marina. Accordingly, she went from there to Syria; on the crossing she was thrown into the sea by the sailors, because they suspected a lot of money with her and wanted to rob it; But Marina was wonderfully saved and then lived for three years under the name Marinus in a men’s monastery in Syria. After her return, she died in Sicily.
Joachim Schäfer: Article Marina von Bithynia, from the Ecumenical Dictionary of Saints – https://www.heiligenlexikon.de/BiographienM/Marina_von_Bithynien.html