If your wife's colleague is spending the week at home (what is called Sitting Shivah) and she does not live too far away you can go to visit her. She will be sitting on a low chair and mourning the loss and people will come and go all week. Normally only family and close friends go to the Shivah on the first couple of days but after that anyone who wants to share their condolences visits. Once there the best thing is to say how sorry you were to hear the news and to let the mourner lead the conversation. Sometimes the mourner may find it difficult to talk a lot and the conversation may bet somewhat stilted but that does not mean that the mourner does not appreciate greatly your visit.
