Sometimes the bereaved feel cheated by God. Let them be angry. God understands grief. This is a vital part of the healing process. Enforced silence in this regard can be very detrimental and prevent recovering.
Unexpected death takes longer, up to thirteen months and more.
Regardless of how long it takes, we must remain available until the grieving subsides. Do not make a pretense at being interested in the bereaved if you are not. Pre-tense really can hurt. Think how you want to be treated and always seek to be kind. The person honestly mourns, laments, weeps, expresses anger, etc. doing whatever is necessary to break the emotional freeze to ventilate all feelings of distress.