How should I deal with coworker who cant afford to pay her carnote but expect me to drive her home everday?

But yet she will spend her money on gucci bags and prada stuff then say she paid like 600 for the stuff. But she flunked on her car payment and she has the car hidden so the repo man wont get it. What is wrong with this chick I find this disgusting she is 25 yrs old she is not a child.....she has a child too so why must she feel the need to spend money like this. What should I do about her bummin a ride off me