How can I support someone after the death of a baby?

My childless neighbour recently lost her baby in the first two weeks of its life. She is still in a relationship with the father but they do not live together. She is receiving counselling but I am at a loss as to how to react and what to do or say so as not to cause any additional hurt or harm. We are not close but her family lives away and I am probably one of the few people she has daily contact with.