The code for Choice of Romance is here https://www.choiceofgames.com/romance/scenes/
Specifically https://www.choiceofgames.com/romance/scenes/startup.txt then https://www.choiceofgames.com/romance/scenes/OpeningScene.txt and https://www.choiceofgames.com/romance/scenes/ComingOfAgeParty.txt
I’d say consider the possibility of a gender switch, especially if it’s something that you enjoy. Note, it is something I’ve thought about in regards to my own writing and I don’t always like to use it. My first game had a set gender protagonist because that was the whole point.
So if you want to tell just Guenevere’s story then go ahead. I would suggest getting your first draft down first without worrying about pronouns and all of that. It’s easy enough to go over everything after and implement changes.
If you’ll remember from Choice of Romance, they replaced the gender dynamic instead with an age one. They also used life and death mages to simulate Henry’s desire for a specific type of heir. And there were wealth/station factors in play too.
Choice of Broadsides just did a straight flip. Women in the navy, delicate blossoms of men at home waiting to be married. The Choice of Broadsides method would be easiest I think.
Oh I’m glad you’re taking into consideration magic forced love spells being problematic. They really are. It does sound an interesting take on things.