I don't know how to talk to my mom about this? I'm concerned about ther health?

First of all, it is great that at your young age, you have such a genuine maturity about you. I am glad that you have took the initiative to be concerned about your mother and siblings. This kind of behavior isn't one that is normal. You have every right to be concerned. I really think that you should call a "family meeting" with your mother, siblings, and her siblings to support each other and share their feelings about what's going on in their life right now. Designate a certain object as some sort of a "talking stick" and no one else is allowed to speak unless they have it in their hand. Have everyone promise or even sign a contract that they will not pass judgement on anything another says and provide support in any way possible. We have done this in my family and it has been shown to make great improvements in our relationships. Maybe try some family counseling with a psychiatrist, or talk to one that you are worried about your family and need someone else to intervene. Hope this helped!