My friend is ignoring me?

well i am friends with this girl in my cl called leanne and we are like a 3 with amy as well but recently i have been talking more to my other friends who i walk home with and leanne has started ignoring me and in cl has been turning her back to me and talkin to amy. But amy goes off with her other friends and leanne doesnt ignore her. I try to include leanne in the conversations but she stands there and she has been giving me evils and when i say why are you looking at me like that (in a nice way) she says i wasnt when she obvs was. Is it my fault and what can i do to be back friends with her???