Step Daughters grandmother is an alcoholic

This is more of a vent post rather than advice.

I have 3 step daughters. Oldest is 14 and the twins are 11. I knew their grandmother was an alcoholic (SO mother) but I didn’t grasp the extent of it until recently.

A couple months ago we drove to NY to visit their great grandparents (SO grandparents) for a nice dinner and to spend some time with them. SO mother came. We were only there for a couple hours until she started feeling sick. Sweats, shaking a little bit, nausea. She had to lay on the couch so that way she could stop shaking for a little while. We ultimately had to leave after about 30 minutes of her complaining that she didn’t feel good and wanted to leave. SO was visibly pissed while his grandparents didn’t say anything.

Some back story, she’s been an alcoholic throughout his childhood. They bounced from place to place throughout his childhood because she would rather spend her money on alcohol instead of the bills. Whenever she did decide to pay the bills such as rent, she would make him give it to the landlord as an example because they wouldn’t yell at kids. He believes that she’s been drinking since before he was even born, according to his grandparents, she started drinking at 18. She’s also a mean drunk too. She’s smashed phones, tv’s, and a bunch of electronics. She’s yelled and screamed at my SO for not being able to come at her beck and call whenever she has any kind of problem. Whenever you’re near her, you can sometimes even smell it on her. She’s yelled at him about his girls when they were around in the past calling them “snotty kids” and other obscenities.

I only bring this up now because just a couple days ago, the oldest was making fun of their grandmother for not being able to hammer a nail into a board. What she was building, I don’t even know. She said that she kept missing and was swaying all over the place and was walking around “funny”. Now I don’t think she would ever get mean around them it’s just them around, but I am not comfortable at all with them being around her when she’s drunk because of her mean streak when it comes to it. I’ve expressed this multiple times to my SO and he said he’ll talk to the girls’ mother about this, but I feel like it’s just a lost cause. One of these days something is going to happen where he’ll either probably go off on her or just go no contact like he’s been wanting to. The reason why he tells me he hasn’t is because she lives literally right down the road from us and the girls play in her yard all the time. “It’s hard to explain to kids why you’d go no contact with their alcoholic grandmother” is usually along the lines of what he says.

Not really looking for advice, just wanted to vent and complain. That’s really all.