Nina - Wow - a scary and also fascinating dream(s).
I sense this dream is about a feeling of awful loss. It starts with you all together walking in the jungle - a state of your natural self which often needs getting used to because in this state you meet the lions, tigers that are now free and interacting with you. In other words feelings, fears, no longer masked by civilised surroundings.
Suddenly the lion you react to as threatening - but that is because you are afraid of your own fears. The following shows how it could have been met if you were not afraid.
Example: I had my first lucid dream when I was quite young, maybe 5 or 6. In it I was myself at the time, a small child and I was alone in a jungle in the daytime (I knew it was day as I noted that it was somewhat light through the deep tangle of lush plants). I was alert in this exotic environment, but not afraid. All of a sudden a large adult tiger appeared directly in front of me moving towards me. I was quite startled and aware that I was in a very dangerous situation. But I just calmed myself from within, and at that moment, I was able to tell myself that it was ok; I was in a dream and the tiger would not really hurt me. Then I was able to face the tiger directly as an equal with no malice. I don't know what happened after that, or if I simply awoke, but I know I never considered that dream a nightmare, and I have always remembered it. P.
In our dreams, every thought, every shade of emotion immediately becomes a physical reality. Your anxiety - the lion - was immediately formed into the actions that followed - you run away, which is never a good idea in a dream, because dream images are only your own feeling out into objects, actions and things; so you were running away from you own anxiety.
You go into a tunnel - a period of your life that is limited, probably because if your enormous dependence on your mother. It also represents an attempt to hide by being unconscious or not aware of what you were doing or was involved in.
What you were involved in was the fear of losing your mother - the lion killed her. It probably happened that about the time of the first dream there was something that set the fear in you, a terrible shock for a child, that your mother could die or leave you. So afterwards you had not faced this fear of her death and so it appeared often.
Your cousin saw her aunt who was an important and supportive woman to her. You dreamt the same dream because you have a living but inner and outer link with her and share the same fear.
To stop the dream happening decide to face the lion of your fear by using
http://dreamhawk.com/dream-encyclopedia/secrets-power-dreaming/Tony