I've never felt that Nandini was innocent.All she wants is to take everything that Mauli has/had.Now that she has Kunal she will definitely try to get into good graces of K's mom and dida.
I also feel that it's not about divine love.There has to be something more because I feel if the writers can create a brilliant character like Mouli they could also have created more sympathy for Kunan.But whatever Kunan do ends up creating more anger towards them.As you said Nandini might reveal her true self later.