2. She puts other people above you
Sometimes, even if your girlfriend likes you, she can prioritize other people over you, which can be hurtful. For instance, she can cancel plans last minute, end your phone call to talk to other people or behave more cheerfully in the company of others. Unfortunately, this is the sign that she is not really in love with you. The woman in love would be blossoming around the man she has feelings for, and try to spend as much time as possible with him.
It is alright if she wants to hang with other people or take some time away from you. After all, you are two separate people with your own lives, even if you are a couple. But if it is obvious that she gets more enjoyment and inspiration from other people, the problem is one of you. It is either you failing to deliver her emotional comfort and enjoyable pastime, or her not truly being in love with you.