You think we look alike? Our hair has a similar colour but I believe that’s about it. Of course, we share some other similarities because we’re Hylian, perhaps that’s why you are confused?
At a first glance, you might think Zoras all look the same but if you pay close attention you’ll start seeing differences. The Zora obviously can see these things instantly. I think it’s the same here. You it’s something you have to learn to notice.
As for me and Link. I don’t think we are related. The biggest giveaway is the shape of our ears. While Link’s ears are a bit rounded, mine are more slender. It’s a known trait of the Royal Family.