Faking Bronchitis To Get Off Work?

This women I work with took a month off work last year claiming she had broncitis. It appeared to of started over the weekend and she just happen to get better over the weekend (4 weeks later). When she got back to work, she sounded completley normal. Then, 2 weeks ago she got "sick" with "bronchitis" again. It happend over the weekend (Friday was was completley fine), and she was off for a week claiming she couldn't talk. She came back on a monday and you could tell she was faking her voice just because one minute it was scratchy and the next it was fine. My boss said she was going to fire her after this time because she is very unreliable and I agree! But no, of course, she never got fired because they just "cant do it". Not only that but her attitude is terrible, she is always angry. She really hates her job and she is in general a rude obnoxious person. Any advice, or experiences anyone wants to share with me? I'm the one that's thrown in the dumpster here because I have to do 2 peoples worth of work when she pulls this ****. I'm the only one she's not fooling apperantly. Makes me want to quit, but I need the money.