I'm jealous of my cousin 😓

So I have a cousin who's about a year younger than me. We were really close when we were little; we were even pen pals despite only living 15 minutes from each other. As we got older, we got in with different crowds and started drifting apart. Now, she's best friends with her other cousin (someone I was also closer to when we were younger). Is it wrong to feel a little jealous? I mean it's not at all like I want them to stop being so close...I guess I just want that same kind of relationship again. How do I, for lack of a better term, rekindle it? Without being weird about it, I guess..haha I'm so sad 😅