Well Jiji was just a sad woman who was jealous of her own sister and wanted to destroy her life and steal her husband.
Seeing is from Kalika's POV: Narpat is the man who has made her mother a vegetable.
She grew up with the title "Illegetimate" on her
She never had her mother to protect her from the world, give her love, fuss over her, and make things better whne they were bad.
If someone says something bad about my parents, my blood boils and I feel like punching them out. I can't even imagine how she must feel after seeing her mother like this.
So in this situation, she wants revenge from him, to make him go through exactly what her mother went through, though it's wrong, I can understand why.
And when a person is in hate, they don't really see right from wrong.
Even if Kalika does somehow damage the family, or their lives, I know that she will later re-build it and start loving the family too. She won't be like Jiji, who just knew how to hate and not love
Yuks