Friend ignores me, is cold to me

My friend L. and I are in a group of 5 friends. She only talks to me when she has to and never voluntarily asks about my life. She likes/loves EVERY. SINGLE. PICTURE. our friends post. She NEVER likes a single thing I post. And she used to love a lot of my posts. I think she unfollowed me. I have no earthly idea what happened. She used to be so nice to me. I recently had a baby. It was some time when I was pregnant when she suddenly started acting this way. I have been nice to her and everything. I'm done trying to "win" her back. Whatever it is she's mad about, it's extremely petty. Or she's jealous of me. She had stopped talking to another friend recently.

It really bothers me that I still have to see her and she's mad at me and I don't know why. I don't wanna deal with her drama and pettiness, but she's in the same group of friends. What would you do? I'd bring it up, but I feel it would be awkward for everyone.

(I can't reply anonymously, so I will reply here in this post.)