What comes to my mind when I read your thoughts is that you feel that you may be able to... someday... forgive yourself for not stepping in, but that you're not so sure about forgiving your siblings. And, you aren't sure how or if you will ever be able to relate to them again. My question is basically: do you think you will eventually want to, someday far far down the road? Or do you not know yet? Do you imagine that you will want your kids to have relationships with the family? If so, then the goal will someday be to work these feelings out and accept the fact that they didn't know what the right thing was to do, didn't do what you wish they would have, you weren't able to step in, and the result was this horrific loss. Eventually, being able to delineate your feelings from your thoughts, and compare them your eventual plan for resolution, will be an important approach. Let me explain:
Some folks navigate through life by feelings, allowing their emotions and gut level reactions to determine their course, and to determine how they will behave. Some folks are able to observe their emotions rise and fall, respect them, and then choose whether or not expressing the emotion and acting on it is the best course. Some folks are primarily thinkers, and they use reason and rational thought in navigating through life. From our brief relationship, it sounds as if you are the "feeling" type, and so you are used to navigating based on how you feel, and acutely aware of how others make you feel, and sometimes, yes... this type of reaction to the world is a little more self-focused, as you mentioned. Right now you seem to feel "orphaned" and angry and sad, and it sounds like you think there must be some consequences suffered by those responsible for her death and your grief. Feelings are fluid, and thoughts only exist as we create them. They can be changed. You can toss around the idea that nothing is permanent; you may feel and think completely differently 12 months from now. Becoming aware of your own self-talk, what you are telling yourself all day long, the meaning you give to situations, the choices you make in how you choose to define and to look at things... this awareness is extremely valuable in gaining some power over the feelings and thoughts that feel right now as if they have ALL the power over you at this moment. It may come easy to change your thinking or it may be a struggle. You may be afraid that if you let go of this anger, you will be powerless and a victim of circumstance, and you aren't interested in that option. But, I will continue to challenge you to LATER, when you are ready, to decide whether your thoughts are in line with your eventual desired outcome.... and if not, to work on beginning to change them.
In regards to the family, I see 3 choices:
1. To refuse to ever have any relationship with them again. This choice will protect you from facing them and re-opening your wounds in the unresolved situation. You would be making a conscious choice to abandon the relationships permanently, and if you can eventually make peace with yourself and get to acceptance of the situation as it is, in your own mind, you won't be hurting yourself. However, If you can't eventually find some peace and acceptance, this choice will damage you personally for your entire life because holding onto resentment and anger will cause you emotional & physical harm in many ways. However, it is a choice, and many people make this one and find ways to adjust.
2. After some time has passed, make contact again, not to discuss the situation deeply, but just to see one another at weddings or funerals and fake it... either still holding on to the anger, pain & resentment personally, or being able to move through to acceptance that you will never trust them again, but refusing to let them take up any space in your consciousness. A "break-up" with limited social contact.
3. Reach out, past yourself, and try to begin the process of understanding why they did things as they did. Listen without judgment (which may be possible much later... not yet). Take your feelings out of the equation and just hear them, hear their regrets and the view from their vantage point... and try to understand one another, accept that none of you can go back and change it, but that you can choose to try to move forward together.
Do any of these choices sound like they fit with where you are now? And, remember: although you may feel powerless right now, you aren't. You have the power to make choices about how you are going to think and how you are going to let this change you, which of course it has and will continue to do.
Keep working hard.... and let me know what these words make you think... :-)