Completely, completely, completely agree!
The whole Aarti being hopelessly in love with the man who abandoned not just her but their unborn child as well for another woman no less, makes absolutely NO sense to me! Especially since it has been years since he betrayed and left her, I mean I can't even imagine how she can even fathom the idea of taking him back at the drop of a hat. How can she forget everything he did to her? Everything Ansh had to suffer because of him, everything his parents had to go through after he walked out on them, how can she just pretend that the past 3 years didn't happen and just let him walk back into her life? Where is the self respect? I get that he was her first love, and you can't forget that no matter how hard you try, especially since he was the first person she trusted and let in her life in such a big way, but to still be willing to immediately forgive that person and forget that he ruined her life, yeah that goes over my head!
The memories that she keeps going back to are not the ones that she should be remembering because that is NOT how things ended for her, the ones that she needs to be revisiting are the ones where he left her, the moment the world as she knew it crashed all around her, the moment that she realized that he won't be coming back and that she will have to raise their kid all by herself. She is focusing on the wrong part of her life, because that is just a facade to what the reality is, something that Aarti is still unwilling to accept after all these years. So the purpose of this visit really needs to be something like her her questioning Prashant why he did what he did, that is what's going to make me happy, because she has the right to look at him straight in the eye and ask him why, and more than that she deserves an answer. She needs to know that there wasn't anything wrong with her, she wasn't the one at fault for their failed marriage, because she is still holding on to the idea that there was something missing in her which is why he left her. Today's episode needs to be a wake up call for Aarti, this meeting needs to actually work in the favor of her getting married to Yash. Prashant needs to show her his true colors once again, refresh her memory to how cruelly she was abandoned because she is really doing everything she can to overlook that. He needs to display his selfishness, or make some kind of demand or comment that helps Aarti close the door to her past, because that is what she needs, a closure. She has still been so hung on to her previous relationship that she really can't move on until she has finally closed the door on it, something that can be accomplished tomorrow.
It is only once Aarti realizes that Prashant truly isn't worth it that she can actually start trying to accept her remarriage with Yash, and since we know that the marriage is indeed taking place, then I see two possible scenarios: 1) Aarti never gets a chance to go see Prashant, that would be pretty terrible because then the burden and unwillingness to get married again will increase inside her, and she will be even more against it, with constant questions of what if. A big part of her believes right now that Prashant has called her and asked her to meet him because he wants to give their relationship another shot, and as crazy as it is, she is willing to give that to him in a blink of an eye, so if she doesn't get to hear what he has to say, she will begin to resent this marriage and Yash even more because she still has that hope in her heart that she can get her first love back, and 2) She goes to meet Prashant and he ends up saying or doing something that ends up shattering the illusion she had of him in her head, maybe he makes the demand of Ansh's custody to be given to him, or something equally disgusting that snaps opens Aarti's eyes to the rude reality that is Prashant. This is the only way she can go back from this meeting and agree to get married, in fact this will strengthen her resolve because she will know for sure now that Yash is Ansh's best shot at getting a father that he truly deserves, because Prashant is NEVER coming back! I can't imagine her going through with the wedding is Prashant turns the charm on and plays on her emotions. In reality he actually wants nothing to do with her, and he was blissfully ignorant towards her and Ansh for all these years because he knew that she was still stuck in a rut as far as her life was concerned, but the second he gets word that she is actually starting to move forward in life towards a new beginning, his male ego immediately reared his ugly head. He is allowed to leave her and start afresh with another woman, but the second Aarti walks down that road he feels like he has lost the game, and so the untimely call to completely take her off guard and manipulate her through her emotions!
And lastly, like you said, the more that she starts coming to terms with who Prashant really was, the more she will come to admire and respect Yash once the wedding takes place, because Yash is EVERYTHING that Prashant wasn't and that will become obvious to Aarti very, very quickly. I think it is only after this marriage that Aarti will realize what it really means to be a husband and a father, and then when it will come to comparing between her past and present in her head, she will start to lean more towards the present and move away from the past. But for that to happen, like I said, she can NOT enter the marriage with the notion in her head that there was a chance she could have salvaged her relationship with Prashant, that is going to turn her blind towards all the positives of this new relationship and will make it almost impossible to not only accept Yash, but the little girls as well and that is LAST thing we want to see! So it's only if the relationship begins with a clear conscience on her side that she can slowly start adapting to it, and I really hope that we get to see her finding some kind of answer and closure tomorrow, because she deserves and needs that more than anything else right now!