She's not mad, she's afraid.
Even my sweetest balls will hiss sometimes, usually if a startle them or they are in blue and cranky.
Be patient with her, give her time to adjust to her new surroundings and to you. Everything is different to her, and it make her insecure. Gentle occasional handling sessions, for a few minutes at a time will help her to realize you aren't going to hurt her. Go slowly and give her time, and she'll come around.
Gale