Gauhar didn't take part in the pooja then that's fine. It's her decision. Nothing wrong with that.
It's not like she made fun of it or said anything rude.From what I saw, she was standing there and did stay until the pooja finished. She could have gone in another room and sat silently but she didn't do that.For me, even though she didn't take part in the pooja, she did respect the culture and pooja and that in itself is a big thing.If you are different religion and do not wish to take part then that's fine as long as you don't disrespect.And if you do want to be a part of the pooja despite being a different religion (like Elli and Asif) then that is also fine.