Now that Ridz knows that her mother i.e Padma was ditched after falling in love and ruined her life, she probably doesn't want to go down that way and wants to make Shashank proud of her... This must be the new reason. The old one being Armaan was fooling with her; so she didn't trust him then.
In the rehearsals for the heer-ranjha stuff, Armaan says something like why should heer agree to marry someone else if she loved ranjha and why did she not runaway with ranja etc etc. And Ridz replies that some people have majboori and not everyone is in a postion to love.. So there must be a reason than just reluctance on her part and I think her mother's story is behind it!
What do yall think??