Guys...
Someone mentioned that there was a change in expression when khushi was seeing ASR's father. So its possible that she has seen him earlier. Based on this, what if the scenario is like this?Somehow Mrs Malik MUs Mr Malik with Khushi's mom(the family might have known each other). Blame the MU on chacha malik. Mr Malik unintentionally causes khushi's parents death due to some rash driving or something. He feels guilty and beings khushi home to give her a home during the time of anjali's wedding. So everyone MUs the kid and Malik and the shaadi is broken and Mrs malik commits suicide. Khushi is indirectly the reason in a way.