Maybe she was just hiding her feelings? some people hide their feelings because people look up to them and when they show weakness then some people will try and take advantage of them or then the other person feel weak. I think she just got overwhelmed with what was going on in her life and then when she saw Humphrey open up to her she finally realized that she could finally not worry about the pack and be herself. because she can be herself around him and not have to worry about him judging him for not acting like a alpha.

i would have never though of it that way.

Love just happens... She may had friendly feelings for humphrey, but the only thing needed to change things are actions.