My sister and I are pretty close and I'd even say she's the person I care about most in this world. We've obviously had plenty of petty sibling fights, but I could not imagine life without that lil weirdo.

Not a lot of people immediately pick up on us being related. We're usually seen as friends rather than siblings. I'm pale, with reddish brown curly hair with a big nose and ears. She's a bit darker where her skin tone makes her look a bit racially ambiguous with her straight black hair and her small facial features.
To put it simply, we don't look too alike. We've always chalked it up to me taking more after our dad and her taking more after our mom (which is definitely true when you compare the baby photos, she looked identical to our mom!). But we recently both took a DNA test for funsies since it was on sale and according to the results... it turns out that we do not have the same dad.

She's not at all shocked about it and when I think about it, neither am I. Our dad is still her dad to her since that's who raised her. And we are definitely still siblings, doesn't matter if we're half or full.
But I'm just a bit worried about what this may mean for our parents. My dad knows we took the test and he had taken the same one a couple years ago when he found out he had a half brother, so he's also in the database. I am showing as a match for him now, but he may start to wonder when she'll show up. Also, it may be worth stating that I am the oldest of the siblings.
Our parents' marriage has been pretty rocky in the past, with plenty of threats of divorce. But things have been working out recently and it's felt like we are a normal family. This discovery may just throw a wrench in that.

I don't really expect any responses? I just mostly wanted to get my thoughts out. I did not expect to learn something like this from something we just did to see what spicy flavors of white we are.