Francis has been a man's name for centuries. Ever heard of St Francis?? Eco-warrior and champion of poor and outcast people. Pretty impressive namesake.
It's one of those names - like Dominic, Benedict, John etc - that has male and female versions, also established for centuries.
FWIW Shirley was originally a male name. It mans 'bright meadow'. It only became used for girls after Charlotte Bronte gave the name to her unconventional female heroine in a novel published in 1849.