The thing is, Indira doesn't know Rishi at all. We the audience are seeing the mystery side to him, the fact that he is somehow interested in Indira, and are speculating about him being her love interest, etc. But she only sees a man she got off on the wrong foot with, but had to keep as tenant due to financial issues. She gave him clear rules, and defined his space.
He kept interfering in her life, asking questions about her father, her birthday etc. Then he went and released her brother from jail and became a hero for her family. Everyone just forgot that Munna forged papers, and treated her like pariah for not supporting him in his crime, and this tenant started behaving like he was her family's saviour and she the outsider. Today, yes, he was nice to her, but at this moment, if I were her, I would be thinking what his ulterior motives are. And if a tenant had made random flirty comments at me after a simple accident (god that scene was unnecessary, it doesn't happen in real life, if a girl slips and lands in someone's arms, there is mutual sorry and thank you and they move on!) he would be out on his butt.
Look at this from Indira's point of view-- this man is her tenant, not her future love interest. Why should she like his interference in her family and her family's easy acceptance of him?