Some spiders have much more of a wobble than others, and it sounds like yours has a pretty prominent wobble. Since you've only had her for a short time like Brian said stress could be making it much worse. Try leaving her alone for a week or so. Mine has a slight wobble but her head goes nuts when she's getting ready to eat. I actually keep a small hide in her rack for her to feel more secure (she's only 105 grams).