How do i make up with a friend who is mad at me..?

i saw my best friend in a bagel store. wesaid hi and she asked where i was going and i told her the beach. then i was talkingto her mom and my old friend who im not friends with anymore walked past me and just looked at me.when she sat down with my othere friend, i gave the old friend a dirty look.now my friend thinks i gave her the look and is mad at me. idk how to make up with her..i already apologized but she's still mad.helpp?How do i make up with a friend who is mad at me..?
While the dirty look thing was perhaps a bit caddish on your part, this so-called friend of your does not sound like much of a friend at all. Moreover, it sounds to me that there is enough immaturity here to go around. Stop it. Life is too short.