Priya is not spiteful at all.
She could have been mean about Kishwar too. But she just expressed her honest opinion about everyone and everything.
Princy gave those bruises to Priya during task. In the adalat task, Priya told him that he should be the last person to talk about humanity because of what he has been doing in the name of task.
That make princy shut up properly.
In the Adakat task, when Prince asked her a question, I found it unnecessary for her to taunt Prince - she was in the stand, and her focus should have been to answer the question instead of taunting others