At least tell her son he's a piece of shit and what he's doing is wrong, get in touch with the parents of the kid just out of high-school who suddenly moved into her home.
She has enabled Ralph her whole life so she's obviously not going to start confronting him now, but I can't understand how any parent can see their 34 year old alcoholic/drug addict/felon son suddenly brings in a kid just out of high school from across the country to live with them and they don't do anything about it.
I understand the woman is sick but no one is asking her to wrestle Ralph just set him straight for once in her life.
Also, it's been about what, two years since he got out of jail? He's become a full blown alcoholic while mixing booze with drugs, he's become morbidly obese, lost his wife, his health is worse than ever before, he's lost his only source of income and has what amounts to a minimum wage job now, he's been exposed in national news, etc. And that's only after getting out of jail.
Things have spiraled very badly for Ralph, any of the facts above would concern most parents, but he's suddenly gotten himself a live-in teenage girlfriend and she seems to ignore that along with every other red flag.