Truth alone triumphs. She has played the double standards game when it came to telling the truth. She is an adult and should have stood up to her father's coercion to hide the truth. Prof. has never been right in his pragmatic advice to his children. He told Adarsh to keep Komal away which led to them being on the outs in their marriage. One minute he tells Prats Krishna di ka achcha hai, next minute he is asking her to hide the truth from him. Even after Krishna poured his heart out to him in jail, Prof. didn't think it pertinent to tell him the whole truth. He is messing with Prats's marriage and she has blindly trusted her father. One sure sign of maturity is being able to stand up to parents and adults and speak the truth even if it may not be in her best interests. She will have faced the situation head on and dealt with the fall out and rebuilt the relationship.
One way or the other the truth will come out, and if Krishna is going to behave the way the Prof. expects then it can happen even later on. So how is it facing the situation head on? The Prof. lives in fear of society and he is sabotaging his children's happiness bec' of his own insecurities, fears and lack of pragmatic skills.