From the 1906 book of baby names again, this time focusing on gender:
Florence, Marion, Shirley, and Vivian showed up on the lists for both boys and girls. In fact Marion was the name given to my great-aunt who was born around this time. I wonder if it was thought of as a "unisex" name at the time? Her older sister had the traditionally-feminine name of Katherine, but her younger sister was named Frances, so maybe her parents moved towards names of somewhat ambiguous gender on purpose? The brothers had traditionally-masculine names like Joseph and William.
Anyway, Evelyn and Frances were listed in the girls' section, and not in the boys' (even Francis). The girls' side also had the nickname Frankie; Merle, which I always associate with male singer Merle Haggard; and... Flavil. Like the mouse in An American Tale, right? Who was male. Possibly they spelled it Flavel. But there was no similar name on the boys' side of this book.
It was hard picking out names from the boys' list, because so many boys' names have been used for girls. Like the book had Emery for boys. Could you use it for a girl today? Sure, I think it would be cute, and I'm sure people have done it. But it's not like I saw it and thought, "Emery? Isn't that a girl's name?"
The boys' side had Carroll, Clare, Dana, Leslie, Lindsay, Sidney, and Tracy; none of these, even with a different spelling, were listed on the girls' side. The girls had Caroline and even just Caro, but no Carol; and also Clarice, Clara, Clarissa, and Claribel, but no Claire.