I feel something bad happend to birwa that why she is like she is... maybe she got raped by sarang some years ago or something like that :)
http://www.desi**fo***.net/index.php?option=com_content&task=view&id=59367&Itemid=163
http://www.desi**fo***.net/forum/bandini/86066-bandani-main-naya-twist.html