Glad to hear! If someone really connects with one of these characters, it always makes my day for sure. Marina is probably my favourite character of the whole cast too.
As for making it canonical - I think it more or less is canon already. I mean how else would you read the info presented in the game? I've heard some people argue that she just dresses like this in this moment in time, but Marina's ending shows clearly otherwise. If the game was set in any more modern setting, I wouldn't mind labels, but I don't think in the 40s they had modern identity vocabulary. Besides I kinda like how it is presented in the game currently. It's not emphasized or understated, this is just how Marina is. Hope this is understandable and doesn't feel like a cop out, as I'm certainly not trying to brush it aside.