Is it normal that i feel uncomfortable around my own family?

So, I have 3 siblings, a sister-in-law and a brother-in-law, you'd think I would be close with at least one of them right? Nope. I feel just as uncomfortable around them as I do around strangers (same with my parents). I can't sustain a conversation with any of them. I feel we have nothing in common, and I can never think of anything to talk about. Sometimes I think it's normal since I am the youngest and there is somewhat of an age gap (from 4 years to around 12 years), but I know so many people that are the youngest and are very relaxed and comfortable around their older siblings.

There are times we all eat dinner together and I have something to say but I just keep it to myself because I know no one wants to hear it. Also, there have been times I try to say something and they don't pay attention and talk over me, so I just don't talk anymore. It gets worse with time too. When I first met my sister-in-law we would talk sometimes, but now we never do. We sometimes don't even say hi. They all just ignore me now.

The last time I can remember being friendly with my brother, who is 4 years older, is when we would have pillow fights when I was like 7. I really don't understand why we aren't close at all. But I wonder is that normal?