It's strange but very common, how months after, even years later after someone dies, we still grieve them in our dreams.
The word grieve comes from the Old English word, "berēafian" meaning deprived of, which is exactly how we feel when someone dies.
For whatever reason you grieve, you might try to work it out in your dreams. You may surprise yourself when you find out you're still dreaming of your long lost aunt, who died twenty years ago, thinking "you've gotten over it." The stronger the emotional ties, the longer Grief lingers and dreaming of her could last a life time.
We are expected after a loss to; pull ourselves together, put on a brave face and to get on with life as quickly as possible. Yet, if we don't grieve enough about our losses whatever they may be, or allow more time to come to terms with death, then the deceased one or the object of your grief could possibly haunt us for the rest of our lives and we wouldn't want that to happen, now would we?