person A: You know my parents still have not gotten over the loss of my sister.
person B: Oh my gosh_comma_ I'm so sorry. May I ask how long ago it was that she passed? 
person A: She passed two days after Christmas. She was very sick during the whole month of December.
person B: They probably still just need some time. My grandfather still isn't over the passing of my grandmother and that was over a year ago. I would just make sure to keep seeing and talking to your parents to make them feel as loved as you can.
person A: I will_comma_ and thank you so much for the encouragement.