yes Krishna is Arjun and Bhumi's kid but Shefali puts Bhumi in an accident so she cannot Have a child because her uterus is destroyed or weak or something so they do invitro - fertilization and put Arjun and Bhumis kid in Shefali's uterus so that she can give Birth but the kid has Arjun and Bhoomis blood in him.
Meanwhile doing some mantra on Arjun Bhumi's photos in the bedroom she makes them all Arjun Shefalis photos and shows them to Bhumi telling her that the kid in her womb is hers and Arjuns. Bhumi believes her as when she comes back she sees that Arjun allows Shefali to do her manmani in fixing the kids name and nobody remmebers her even Arjun.
So now she wants revenge
Frankly i agree with her
I hate the Goenka family - i mean when i see the old videos where she helped Mansen, Vishaka, Baisa, Gunvati, Shakuntala and moreover the whole family to get them together and they dont even remember her now that shes dead - i mean she spent her entire life living for this family and what do they do when shes dead - erase her identity completely and for whom? Shefali who has plenty of evidence in the past of being wrong - the same person who threw Bhumi out of the house and threatened Shakuntala to release her secret and Baisa knows about Shefali why cant she connect the dots to see that this is exactly what Bhumi had said that Shefali wanted... i mean why cant Arjun realize that Bhumi always said that Shefali wanted to marry Arjun and get him... why doesnt Arjun instigate Yuv and Shefalis marriage again or why cant he raise the fact that you knew this was going to happen after the child's birth and what if Bhumi was alive today?? You would still be having no-rishta in this house what would you have done then??