<human>: Give me a shortened version of the text

Hey guys, throwaway account, because well, I kinda need to.

So I have this friend. Let's call her Sarah. And another friend, who we'll call Ellie. The three of us have been best friends since high school, and it's been a couple of years since we graduated but we still talk every day. Or at least, we used to.
Ellie recently got some new friends. Good for her, right, because they have more things in common than she does with me and Sarah. Almost every time we'd talk to her in the last month or so she'd say, "sorry, busy, with *insert new group of friends here*", or ignore us altogether. As I type this, we haven't spoken to her in five days, but we know she exists because she's still posting on Facebook and Instagram and what not. If she's mad at us (I don't think that's likely) I couldn't for the life of me figure out what we did.
Sarah and I haven't spoken about it. But it's getting to me because, I really miss her. I get she has new friends and that I shouldn't be jealous, but I am. 
I know this sounds like a stupid schoolgirl kind of problem, but I'd feel too awkward bringing it up for fear of sounding clingy or jealous. Do I wait, talk to her anyway, or just give up on her?
<bot>: Friend has new friends, ignoring me and her other best friend because she's busy with them all the time. What do I do?