Grief is not a queue you join and leave. It arrives in waves, disappears for a fortnight, and comes back in a supermarket aisle over a brand of biscuits. That is not a setback and it is not a sign that something has gone wrong.
What people often need is not advice but somewhere the person can still be talked about in the present tense, out loud, without anyone changing the subject.
There is no point at which you are supposed to be finished. Most people find the shape of it changes long before the size of it does.