Vansh was not there when half of the things happened. How will she show him any evidence?
Also, she would have shown the box to him once she saw the contents herself...not before. But before she could see it...the box was stolen.
So I think...Riddhima is completely on track here.
This is also not my point ...my point is I can't justify at all her still favoring kabir & keeping connection with him & believing him after her growing feelings toward vansh . I'm very much disliking this part of ridhima