Your concern for your friend’s well-being is very touching. Caring for the people that matter to us is one of the most important things we can do.
I know you said that child protective services had been called. But sometimes it is important for them to have multiple sources of complaints. I would I would use their hotline to explain what you’ve explained here to them. At the very least it will give them another indication if something’s not right in your friends house.
Next, I would talk to your high school counselor. I would talk about the stress this is bringing to you in hearing about all of this. High school counselors are well versed in understanding these types of issues, and helping together resources.
Again, I admire your desire to help your friend and help the suggestions help.