Dear Pittuchen,
Om Gam Ganpataye Namah.
I am deeply saddened to read your post. The karmic debt your families are experiencing is unimaginable and my heart goes out to you. But this is the human condition and we must cultivate acceptance and humility in the face of God's true wisdom and justness. To lose faith in the ultimate fairness of our lives is to turn our faces away from the truth of divine creation. And in the absence of understanding we must rely on our faith. Like someone said, trying to comprehend our karmic backlog is like trying to teach an ant the internet. It just isn't possible.
As regards your astrology research, you are quite correct in understanding that 'one's charts could give an indication of parents and siblings as well as spouse's and children's health and well being' - and so they do. But your answer is contained within your question itself. It is an indication.
For instance, your 11th lord Venus, representing elder brother, is afflicted by being in the Nakshatra of malefic 8th lord Moon and also by conjunction with a very powerful malefic 12th lord Mars, capable of causing health worries and loss. And if you see it using your 11th house as your brothers lagna, the 6th lord Jupiter is in the 5th (12th from the 6th) afflicted by Rahu and exaggerated by being in Rahu's Nakshatra as well. Rahu gives health issues that are either near impossible to pin-point and diagnose or, if diagnosed, very hard to cure.
So these, among others, are the indications you correctly speak of. However, to accurately predict basis time lines and eventualities is best addressed with the natives own chart. To exchange information on the basis of whim or fancy would be a harsh disservice both to you as well as to this profound and ancient science. I trust you will understand
Thank you for your more than kind words, they are a great source of encouragement coming from one both elder and wiser than I. You put me at a disadvantage though, for I doubt there is anything of value or learning you could ever hope to attribute to me. I, however, am always ready to learn from your rich experience and wisdom.
God bless.