My team have a big task to do. My colleague keeps making passive remarks about me not helping with the task and I am helping but I have a different role to do in the task so it is taking me a lot longer. I have explained to her what I am doing but she is not interested. She keeps shouting out random passive aggressive comments. Yet other team members are making sure they go walkabout and chat to other colleagues and not do any work or work from home so they are not helping yet she doesn't target them. What is the best way to respond to this situation? This person is not my line manager and my manager is well aware I am working hard. I actually feel I am working too hard and rushing and burning out yet this is the way I am being treated with nasty comments.