I am so sorry for the loss of your precious niece. I did not know her, but I know how I would feel if I lost one of mine.
To her parents, God be with you as only he can help you through the days and months ahead. Minute by minute your feelings and moods will change, just be patient with one another and allow yourself to grieve. God has her safe in his hands and she is looking down on each and every one of you. Prayers towards her children as they try to accept this major change in their lives.