What to actually say
Open with this, more or less word for word: Mom, I don't want to talk about moving you anywhere tonight—I want to talk about the stairs.
I'm not here to decide anything tonight. I want us to look at what's actually happening in the house, together.
Lowering the stakes up front keeps her from hearing a verdict she has to fight.
You fell in the kitchen in March and didn't tell me for two weeks. That's the kind of thing I need to know about, even if it's just a bruise.
One specific, undeniable fact does more than any general worry.
This isn't about whether you can take care of yourself. It's about whether the house makes that easy, and right now I don't think it does.
Separates the house from her competence, which is the thing she's actually defending.
I know the words 'assisted living' land like I'm trying to put you somewhere. That's not what I'm bringing tonight—I just want to name the problem before we talk about any fix.
Naming the fear out loud takes some of its power away before it can hijack the conversation.
How it usually goes
A version of the conversation with the push-back left in, because that is the part you need to have already heard once.
What not to say
You know this is for your own good.
It confirms the exact fear she has—that the decision is already made and she's just being informed.
You can't live alone anymore.
It's a verdict, not an observation, and invites her to defend the whole rather than discuss the part.
I just want you to be safe.
It's vague enough to sound like a justification for taking over, which is what she's bracing against.
If she shuts it down completely and won't engage again
Don't chase her back into it that night—pushing when she's gone flat only teaches her to shut down faster next time. Let it sit, then come back in a few days with something small and concrete instead of the big topic: a grab bar, a stair rail, a med organizer. Say, 'I'm not bringing up the other conversation—I just want to get a rail put in this week.' Small, visible fixes rebuild trust that you're solving problems, not building a case. The bigger conversation goes better once she's seen you do that once.