Priests differ on this . Some will say what your ICRSS priest said. Some will let you have the patron saint of opposite gender but will make you change the name to the correct gender form (for example if you’re a man and want St. Joan of Arc then they make you take the name John). Some don’t care and let you have who you want.
You pretty much have to follow what your priest says. But keep in mind that although he may not let you take a female saint other than Mary formally as your baptism saint, you can still pick as many patron saints as you want to be devoted to in your private life.
St. John Vianney’s favorite saint was St. Philomena. Obviously she wasn’t his baptismal saint. But she was his best friend.
So just follow what your priest says for baptism but then you can pick whatever saint you like to be your own best friend.