One of the most important people in the life of a person is the sister or brother. The relationship between a person and their brother or sister can be very close and incredibly eventful and important. Of course if a person does not have a sister or a brother this does not mean that their lives will be any less fulfilling, but for those that do, they may find it hard to function without them, therefore a dream about a dead sister, death of sister, or a dead sibling can be very hard to handle.
If you have a dream in which you see a dead sister then this means that you feel like there is something wrong in your relationship with your sister. You may not know what to do just yet and you may not know where to take a dream like this or how to respond but what it really means is just that you need to get back together with your sister and see how she's doing. You are worried about your relationship with your sister crumbling and going downhill. You miss her and you want to see her again and without her input your life may not get on the way it should. A sister can provide guidance and in fact there are many ways that a sister can help your life that a mother or father couldn't even help in.
There are many areas in a person's life that a sister needs to fill in that a mother or father cannot. A mother is a good influence on the life of a son or daughter as well as a father but their influence stands along with a type of fear that is there as well. Kids are just a little bit afraid of what their parents might think of them if they say a certain thing or act a certain way. They also grow up knowing that if they do act a certain way, even if their parents would not normally feel so inclined to get in on their child's business, that they will out of the obligation for being a good parent and making sure that their children are raised in the right way. A sister can also chastise a child but they so it with a little bit more friendliness, since they too know what it was once like to be tyrannized by their parents. Sharing this bond makes the relationship much better which is why the death of sister can be so hard to see even in a dream. This is not a good thing and you can be seriously traumatized by this.
Even if it is not a sister, a dead sibling of any gender can be a pretty serious symbol that you need to reconnect with your sibling or your sister before you lose her or you lose your brother. They may not die, but you really do need to establish a connection with them if only for your piece of mind. If it will help you sleep better then it will help the rest of your family sleep better. Just make sure to pay attention to your attitude and your views and see how far you can go with it or else you will get yourself into trouble.