I Hate a Co-worker

She makes me f*cking crazy. She is 47 years old, and has worked here for 7 months. By now, she should be all caught on, and know her job well. Instead, she constantly makes mistakes, goes to HR if you politely correct her mistakes and says you're picking on her, gives out wrong information to commercial customers that are doing several hundred thousand dollar projects using our material, she pretends to work and then when you run her numbers, she is FAR behind everyone else, spends her day shopping on Kohls.com, randomly disappears from her desk, has failed ALL FOUR of the job knowledge tests we've given her and blamed the person grading them that she failed, she eats more than I've ever seen another human being eat in one sitting, (No joke. BAGS of food throughout the day, everyday.) She runs to HR and complains about everyone here being mean to her, our customers don't trust her, and they STILL haven't fired her!!! She is making so much more work for those of us who DO work, and she couldn't care less. She is totally worthless. She is costing us sales with her constant wrong information that she gives out. Her latest trip to HR consisted of her complaining to them that our supervisor doesn't come "check" on her......WHY WOULD THEY???? Our supervisor doesn't "check" on anyone! If you need help after 7 months in, it's up to you to ASK for it. You're not in training anymore and haven't been for 4 months! God I hate her. I'm tired of picking up her slack and I wish they'd fire her already. She speaks to everyone on the phone as if they're a toddler, tone and all. She sounds ridiculous but in her mind it sounds professional. WRONG. I sometimes purposely correct her when I hear/see her doing something wrong. I know it embarrasses her and pisses her off to no end, but I don't care. She honestly thinks she is phenomenal at her job. She just can't see that she does anything wrong. I take great pride when I catch her making mistakes, and I'm normally not that kind of person. I just LOVE to humiliate her, especially because she already detests me. Several people in the building have complained about how loud and unprofessional she is. CAN HER ALREADY!!!