I think Pragya in this ML track did not volunteer to do anything. When Dadi told her not to stay in MM after Abhi's accident, she left, I do not think any wife will do that, but she did because she loves Abhi truly. And after that she started her life trying to forget him but fate brought her to him in the way of Life Music Company. Then gradually their relationship developed. She did not force herself anywhere, she was happy to be his secretary but since Abhi was getting attached to her, Aalya and Tanu got insecure and started their plans. There is nothing wrong in trying to be with your husband even if he has forgotten you, that is what a dutiful wife will do. But she has villains always standing against her. The only mistake of hers is she always underestimates them.
Abhigaya are not only married but love each other very much (even though Abhi's love is fresh after ML). So, they cannot stay away from each other, they will always land up with each other and always getting into trouble because of the villians. So, only if Abhi gets his ML or happens to find out the evilness of Tanu and her alliance with Nikhil, the story will go on like this with PRagya and Abhi suffering.