If my in-laws are footing the bills for my sister in law, do they have a right to know her job situation?

My sister in law who's married but with out children recently lost her job. We felt especially bad for her given the current econmy and because she dropped out of college and has been working ever since doing retail work at the mall. When she lost her mall job, my inlaws started footing all of her bills so she and her hubby didn't loose their house/cars etc (her unemployement apparently hasn't started yet). We recently found out at from a friend of ours whose company she interview with that she turned down a position with them because she would have to take a pay cut and the position wasn't managment. We were shocked to hear this and even more shocked to learn that my hubby's parents didn't even know she was offered a job. We think my sister in law is being ridiculous in this situation and has some growing up to do. We feel horrible that my inlaws are stuck paying for her bills while she's turning down jobs. Should we tell them what we know or just keep that info to ourselves? My hubby's sister is very immature and spiteful so we're tempted to do nothing. Is this wrong?