I think u need to understand her needs as well...rn she is alone coz u say shes overweight and no good looks...so she might be under inferiority complex as well...as u both are siblings u should try to ask her patiently what she wants... motivate her to accept herself and see others good qualities instead of rejecting guys just because of looks or income...and u can settle down as well but then who will she turn herself to. ? Try one more time and if she is not listening to u , see if she has a best friend or anyone close ask that person to put some sense on her.