I don’t know what to do

So I don’t know what to do, I’ve been married to my husband for 5 years and I just see my SIL getting worse and worse. She’s married to a rich guy who treats her like shit and she’s an alcoholic and does pills.. my concern is her kids. I feel SO bad for the children. They’re in this house with TWO neglectful parents who are too blind and selfish to see they’re fucking up their kids lives. They don’t spend any time with their kids, are always fighting, and she only feeds them mac n cheese and they are ALWAYS sick. The kids are so bad but you can’t blame them that’s the only way they get any attention from their mom. She has no control over the kids and doesn’t pay attention to them at all because she’s too busy drinking and being depressed with her “poor me” attitude.. it’s so bad that my in laws (her parents) take the kids every weekend to their house so they get a break from that environment. The parents are getting older and it’s really hard on them to take care of 3 bad kids.. anytime anyone tries to say anything to her she just freaks out and starts hysterically crying and leaves.. I really don’t know what to do at this point. Do I just ignore it and stay out of it like I’ve been doing or do I try to help these poor kids?? I’m torn and heartbroken for them