It can mean a lot of diffrent things, Like she might love you but she is trying to not to show it.
What does it mean when a girl blushes but does not smile with just you?
Its possible you just made a huge mistake and embarrassed her to pieces for which you need to apologize later when you two are alone and she will let you know what you did and then you may have to perform damage control if you like her and want to remain friends. Good luck