Friendship Jealousy?

OK im not normally one to post about this but I wanted a little...advice lmfao ;-;
I have a best friend, in my small friendgroup I love her a lot and she means sooo much to me, as well as my other friends in the group (which by the way, I'm never jealous of, it's just certain people and it rarely happens) I've had some light trouble with past friend groups, feeling left out and that, so maybe it's to add to what im ab to say? Anyways, Ive noticed when she starts to talk to new people I become pretty jealous. (I'm gonna be honest it's mostly when theyre the same ethnicity) I can't seem to help it and it's obvious that they want to talk to her and not me, that I get silent when topics get off-course from what I'm used to speaking about. Me and my best friend are kind of different so when the person starts talking about stuff she can relate to it forces me to just nod along lmao. but I've always known I have a huge problem with jealousy lmfao, it makes me feel so terrible smh 😭
this girl from my past friend group now found a new friend group, then found them annoying and came over to us, which i didnt mind at first but she does it all the time now, and talks to my friend every chance she can get.
I know this doesnt really contribute to anything and it's just Snapchat 💀 but she and I are mutal besties now (meaning her 1# best friend is the same as mine) which sounds really whiney but whenever i see it a little part of me just feels a little thingy about it, even though its a damn app LOL
The girl also walks home with me, we've always been friends but I feel like she doesn't realllllllllly like me, she's kind of ungrateful sometimes and a bit boastful but I cant really tell if it's in the jokey way at this point. She's still relatively nice, but even in my last friend group we were a bit iffy with her if yk what I mean
she once said 'oh we make a good trio!' when were sitting together at lunch, and I've probably looked into this too much but im my head, I found it kind of obvious that she just meant her and my best friend. idk, I always feel sad thinking about the whole jealousy thing, and it's not even the first time she's done it b4 and I really need to stop myself feeling this way cos despite the manyyyyy friends we have separately, it's just one of them people yk (might I add the girl is the same ethnicity as me and my best friend so maybe that adds to the reason they're close help 😭😭 okkk this was more like a rant and I sound like a whiney brat but writing this made me feel a bit better lmao, even just knowing people could relate is a nice thing 💖💖💖💖💖