It sounds like a good use of a dream sequence for a character. Our dreams do sometimes work to help us "resolve" issues from the past where we might not have "closure," so to speak. Trauma and tragic events can make it difficult to arrive at closure, and dreams can represent a chance for our subconscious mind to take us to a place where we come face-to-face with the need for closure.
Dreams often allow us to relive the situation, a similar but not exact situation, or an entirely different situation that feels similar regarding the challenge it presents. One or more dreams might offer a chance for healing or at least coming to terms (finding "closure") with something from the past. Since we can only live in the present, all of us have to find a way to come to terms with things from the past, no matter how traumatic or tragic.