I don't find anything wrong in Katha's behaviour towards Viaan. She is a lonely widow, her support systems, Falguni and Rewa are mostly for her dealing with issue of Aarav's sickness. We have not seen them discussing anything other than Aarav. So is the case with Dodo. She doesn't have parents and immediate family, except Aarav. and the problem which she is dealing can't be discussed with Aarav.
Basically she is all alone, even being with her immediate support system of friends.
Most importantly, ONS can't be discussed with Falguni, Dodo and Rewa. She doesn't know how they will respond. She can't openly tell what is her issue with her Boss also, as the basis of the issue is ONS.
We get to see only Aarav-Katha or Katha in office scenes. So it is basically a worried mother trying to act to be happy and smiling and an angry Katha on her khadoos boss, or a guilt trip mother for getting late to reach to her son. We got a few scenes of helpless Katha begging in front of PapaG.
OFC, picnic was a bit early for Aarav. But it has been 4 days after transplant and I think ITV norms says the very next day you are back to normalcy
I am okay with the pace and I feel Viaan is doing too much stalking. Katha will burst out one day and Viaan has to go that extra mile to set things right between them
PS: Let us not forget that we know Viaan did wrong, but he is not a wrong person, Katha doesn't know that. To her, he is the boss who took advantage of her for money and is still trying to get close to her in the name of answers and just talking, he is the boss who lied to her to take her to Dubai and tried to spend time for the offer of money