I would have liked to get to know Kary's personal life a little more, maybe have an encounter with her druggie friends while Barny is over at her house. I think that would be a great moment for Kary and her character development. In which she would have to choose to do drugs with her friends, or to protect Barny and keep her promise. Also, when Kary first sees Darrin and Bary at her door, she doesn't seem surprised enough. She later says this is the first time she has seen her son since he was born, should she be more surprised that he is on her doorstep? I liked the part where she lures him out with the chocolate. The only problem was it was obvious that he was going to eat it and get sick. You should always try and avoid letting the audience get ahead of you. I think you have a very good start to a short film here. Keep writing, revising, and brainstorming new ideas.