Quick, I need advice of my fellow demigods!
I (14, daughter of Apollo) live together with my two half-brothers, my Mom and my Step-dad. Since my claiming, two years ago, I didn't know that he isn't my biological father and neither did he, but we're adjusting.
Now, I recently met this unclaimed demigod (14) and I KNOW that's against what you're supposed to do but I fell in love with her, even though she showed since of being a fellow Apollo kid.
TURNS OUT, she is a daughter of Lyssa and of my STEP-DAD (he didn't knew about her).
At this moment, I'm at a quest with her and I'm kinda conflicted on what to do. Should I tell her that I love her? Is that some kind of paradox incest? WHAT SHOULD I DO???
Wow! That really is a mess!
I want to say, everyone, please do not blow up on me or cancel me or something. Nor say anything negative to Claire. This is a very delicate and complicated topic. I'm trying to answer this with as much tact and consideration for all sides as I can, but people will often have very differing opinions on such matters.
So, yes, you're lucky that on your godly side, the two of you are not related. The nice thing about relationships in the demigod world is that the gods don't have DNA, and therefore, as long as you don't share a godly parent, then you're considered unrelated. Because of the incredibly complicated train wreck that is the gods' family tree, it's better to just not think about it.
However, it's on your mortal family's side that the issues really come in. I've heard of situations where a family had a long lost kid and adopted another, who then met and fell in love. Sometimes, they decided to break up, and others, they decided to stay together. Because this girl is the child of your step-father, you're technically not related through your DNA. However, you would be legally related as step-sisters which would be tricky to deal with. I honestly don't know much about law and how relationships with that kind of stuff work.
I think you should tell her, not necessarily because I think you should still be fine, but because this is a situation that requires a lot very clear communication. That kind of communication cannot happen without all sides knowing the situation. Ask her what she thinks is right, share what you think is right. Make sure you consider all opinions with equal weight.
Ultimately, it's up to the two of you to decide what you want to do.
I hope this was helpful and gave you an idea of how you want to handle this situation.