At the confession episode Ashu told her to call him only 'Ashutosh' but she refused saying he is senior to her...so she will call him as 'Suniye jee'.
But I think she used that words just twice or thrice since then but calling him always Sir...
Its fine that she is respecting his seniority but still it feels very odd when she call him sir.
When you love someone you should feel free and close to the person..I think she should call him only by his name 'Ashutosh' instead of Sir or Dr.Ashutosh.
What you say guys!