when posting letter she wes recollecting all the meetings with vikram only. Even though she has a lot of other people to thank to. (rattu, her friend and tinkle, and the nice mami). But at the end when she leave all she was thinking about is vikram. Also one of her memory scene with vikram was the red scarf fallinf on head and in the background the psh music was playing with sad notes which was basically saying that she will miss him terribly.
When vikram had confessed his love he asked her if he is saying anything wrong, at first she said yes and suddenly says no. This all means that she too have same feelings for him. Yet in letter she mentions that she respects him a lot, but in the earlier episodes she also admitted she want some nice and repected person to marry in whom company she can find comfort and not the way her mother is feeling. Also the promos that has been shown shows that after the vikram confession, she find him mor human and well natured because she is the one who is staring at him more.
So guys their are many clues that she is in love too but has not realize her love for vikram.