Many snakes hiss when you take them out. Though balls typically are a little more docile, they are certainly not to be discluded. If the hissing makes you nervous, try using a hook to remove her from her cage. In time she should eventually calm down, though some snakes never do - typically with balls (and a good portion of the hissing population...lol

) this is just a bluff to show their displeasure and try to intimidate you. Hope this helped