Don't mind but I think that this is way too far and if in case this is true then not her but he becomes Malvika's biggest responsibility. And he also said that she knows about Anu which was true and she has issues in her own life which is a point here to notice too.
I have some theories about this
1- either she is the daughter of the person who helped him in his career and he passed away leaving her in Anuj's care or
2- If Anuj's parents died from an accident maybe then she is the child of the other accident victim
3- or even maybe it was him too who took her responsibility after an accident he caused
Rest I will leave in the hands of the writers
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