Welcome to KGGK
As it's been said, the storyline is mainly about the eldest daughter-in-law, Parvati, and all the problems she faces in life. There are a lot of storylines, but currently, Parvati is facing many problems after Om's (her husband) death. She doesn't, necessarily, get treated the same way she would've if Om had been alive.
If you would like more details, visit the Update Archive and it will definitely help you
Preeti