The character of Shrauni is obviously turning negative as the way she has forcefully taken Mangalsutra without either asking for permission or considering the feelings of Manav. More over she was shameless in trying to cement her claim over the elder brother of her departed lover [or presumed lover?].
I suspect future twist may even reveal the scheming father –daughter duo was trying to steal a very useful and honest instrument called Manav for running their business. It was Girish sir who had prevented Manav –Archna from clearing their mutual misunderstanding when Manav had called Archna to their home for the last time by forcefully sending Manav to some client errand.
Inconsistency in the reaction of Manav's entire family in completely overlooking Girish Sir's part in their brother's death (whose phone call had actually drawn Sachin to his fatal accident) and putting entire blame and directing their wrath on Archna is jarring and illogical on the part of 'curatives'.
Samarth