She could have done this way
Milind asks her about the Khangan ans she replies ; It is a gift from my dear friend(Afterall he is her friend now). He asks her 'Kaun' She doesnt reply and he asks her 'Kaha rehthe hai. Mai ne tho tumhe kisi ke saath nahi dekha' She says ' Abh woh mujhse bahut dhur hai. Kash woh mere Samja pathe' and Milind's face is full of questions.
This would have given the story a twist with the imaginary third person in the story. Prachi is meaning milind and Milind is thinking of other person.
Now Milind's mind would work like and wonder is this the reason that Neev and Prachi are not married till now. They might also add up with him imagining the third person as her Pathi bec of the Mangal Sutra he saw earlier. he will assume he left her. He should assume maybe then Prachi is not in love with Neev. So some hope about Prachi and also he would want to get her out the pain. She should lead him into such a conclusion that she doesnt love Neev.
That will clear Milind's mind and will not try to get away from Prachi.