She will talk to you less or not at all.
Less eye contact when talking.
Does not follow through with plans when they are made or attempted to be made.
There is another guy that has been identified as being her new crush.
Less attention to the guy she used to like.
Yeah basically just avoidance most of all. Will purposely ignore questions, Not texting back or one word answers. Girls will always bring one of her girlfriends wen she's alone with you so shell have someone else to talk to.