What if she is the first to realise who Shyam is truly and then somehow forces Arnav to marry Khushi?!
Arnav as always said that he will do whatever for his sister and in the past I have thought that he will marry Khushi grudgingly to protect his sister's marriage plus deep down he also wants her (but wont admit it).
What if... Anjali tells him to marry khushi after she realises who Shyam is and therefore how he is playing with Khushi's family and her. This will of course be after Lavanya leaves (how - I have no idea : either La develops some brain cells and realise her fiance is not in love with her or Arnav calls it off finally).
What do you think?