Legal Advice on Family Problem

hiii ..need your help frnds..i hav a friend whose sister was  married  2 year back but her in-laws are very cruel....They always beat her and ask her to bring money from her home as her husband doesn't work and remain free...girls both parents (mother and father) are dead so she has no money as a result of which she was forced to leave her husband home by inlaws  and snatches baby from her who is of 1 year only. kindly tell me how can we help the girl lawfully and teach her inlaws and husband a lesson. i waiting for your answer..  Thnxss in advance