My name is Cyril so I'm a bit aware of the whole conundrum. It's used both as a masculine or feminine name (more often as masculine) there are some variant Cyrille/ Cyrielle that are more feminine (Cyrielle being the most feminine of the lot) but all three are fine in my opinion. I'll stay wieirded-out each they call the character by her name any way. (it's not a really frequent name I think I met only one other Cyril in my life so it's always wierd when I see someone (or something) called Cyril ^^')