IMO,Ragini was always a weak character!!It's maybe because of the protected environment she was brought up in..Her mom would baby her no matter what!!I would blame that on her...She always needed someone to keep her going..In almost all the times Sadhna was the one who kept her going..Like when Puneet thing happened,Sadhna forced her into dance..She always needed someone!!
Whereas Sadhna,she was always alone..Nobody babied her nor pampered her!!She always took care of herself...Even when Nani forced her to go to her house(When Ragini was getting married to Puneet),she was facing certain problems from some guy..She was still brave to go there alone!!Then with Aalekh..She was always strong!!Nobody ever rescued her from anything!!
Before marriage also,Ragini never showed her strength..Like for eg:-When Kaushi was against the marriage she didn't even take the initiative to speak to her once...She just said that she won't agree!!
Just my opinion,no offense to anyone!!