I think there's a number of things that could possibly happen with the drama at this point.
1) GB could get someone on her side by filling their head enough. Not sure if it'll be Urmi but perhaps more likely to be Anjali and they'l both plot together to present Sandhya in a bad light.
2) Whether or not they both plot against Sandhya together, Sandhya might be warned off Neeraj by, eg, GB. And because Sandhya won't want Neeraj to break apart from his new-found family because he seems so happy with them she'll just distance herself from him or make him dislike her or just get away from him
3) Neeraj might tell Sandhya how he feels, or Sandhya might tell him instead and GB might overhear, or someone else even might. I think Anjali/GB will play a key role in this track, as is quite clear already.
Could Dadaji's business have any links to Ragu? Maybe that's how Ragu so easily let go of Neeraj and how Dadaji was able to find him?
I really don't want Neeraj and Sandhya to go their seperate ways or to end their friendship or tarnish it, but I have a feeling that it will definitely happen :( It's going to be annoying to watch but I don't think this story line would have started unless it's going to be to explore Sandhya being forced to give up all hope of getting with Neeraj or him going against her or something. Up to now we have seen their friendship/relationship going extremely strongly so I think maybe the producers want to show it breaking (although at the end of it they might just end up together) - sounds like a typical drama storyline but I think that's how it'll be :\
Sandhya's response to Urmi was slightly weird and uncalled for. Perhaps she thought she would have to talk about her marriage or something to them? Talking of marriage, none of the family know that Sandhya has been previously married. Another possible track could be that they agree to Sandhya and Neeraj getting married but then GB or Anjali find out that Sandhya has been previously married and reveal it and therefore the family might disagree to the marriage, regardless of the hardships that Sandhya had to face. Actually come to think of it this could really happen :\