should I be concerned about my grandmas drinking habits?

so for the last few years she buys one of those 4l boxes of wine 1-3 times a month. I was in my kitchen tonight and noticed the empty box turned it around and to my suprise it says thats 5 and half bottles. she goes through these in 2 days so 2 and half-3quarter bottles both nights. Im aware shes an alcoholic getting her to stop is outright is out of the question multiple family members including her son wont talk to her because of it so my main question with given context is at the age of 70 i can only think its harming her liver is this something where i should stage an intervention i dont wanna walk outside my room and see my grandma dead from alcohol poisoning but i also dont want to get kicked out of the only roof over my head for overstepping boundary’s. So reddit what would you do in my situation