My wife and I handle the rent, food, her car, and her phone, and her mother handles utilities and her own car. No one else contributes monetarily. Her sister that's here full-time stays with the kids when we work, which I suppose is worth more than money in the long run since we don't have to pay a babysitter who we would never be able to fully trust and would cost too much. Her other sister...oh man, I don't even wanna get into that mess.
Her mother works as a history teacher in Camuy, with a masters in English and a PhD in history...yet she makes less than the average bachelor's degree teacher because the DOE has dragged their feet for the past 5 years in getting teacher raises. The only reason she's stuck it out with them is because they pay for her university classes...otherwise, she would have split for Texas long ago, where she knows she can easily get a job as a bilingual teacher for higher pay.