My family arrived to U.S. in September 2011.
I've heard that everybody should fill their tax forms until April 18.
My sister (19 y.o) worked as Seamstress for 12 months, she quit month ago.
My mom living in family in exchange for some household help, plus sometimes she's does some part-time job at other families.
My question is: How dangerous it is to not fill the forms for future citizenship acquiring, and what if we still didn't filled any forms (that's was our first April in U.S.)
As I remember my sister as a Seamstress has no benefits at her job, and Mom too. Does that mean that my sister should pay the taxes herself? I mean if job doesn't care about paying taxes for employee, then employee should take responsibility, right? I need to know all possible penalties and deadlines.