I don't think she acted in Gunjan-Veera scene. This is the indication for us that she truly cares for her and also for Ranvi. She is at this time in a state of revenge to what happened to her. Unable to know what is good and what is bad. Let her take revenge. I don't want to see Veera and Ranvi hurt but she is the one who finally gets hurt since no one atleast her father apolozises her. I'm sure she'll soon understands how much mistake she did to them and she will feel guilty. She is not a vamp. Just a character which every person too have if their dreams are shattered suddenly. Within a few days, she will be back to normal. But it is so much difficult to get everyone's trust and love again.
This track is much needed at this point:
1.To reveal Veera that she is half-sibling to her brother
2.To develop much bond between Veeba
3.Gunjan to know who cares for her actually and then love them and never hurt them again ever in her life
4.To learn a lesson how wrongly she is thinking and realise the small and cute Gunjan she used to be
5. Her mother never brought up her in good way explaining all things which mothers share with their children. She used to be her papaji's kid but now changed. Gunjan and Baldev got altered. Even Baldev doesn't accept her act, she'll get to know how much wrong she did.
So be cool and stay away from hating Gunjan. Just enjoy the show. I'm also sure that there is no new girl for Ranvi, even if she come just for Gunjan realization. This is the story it is meant to go. Within a few days, Gunjan will be back to normal. This is not that type of revenge shows which we see. Gunjan's grey nature doesn't stay too long.