I don't. We don't talk. Relatives of mine, including one of my parents, sank into vaccine conspiracies, then followed that pipeline to Qanon, and then explained to me how they were waiting for Trump to lead his secret army to take down the government of my non-english-speaking, european country.
I gave them their keys back, I got my keys backs, I blocked them everywhere, I nuked my accounts on the social media they use (and where their posts steadily got worse). It's a hard decision, I still think about it often still (it's been nearly two years), but I will never talk to them again.
"Victim" is an interesting term, but quite accurate. There's such a an effort and investment into converting people to that cult. I wish you the best with your mother, hopefully the other half of your conversations is more pleasant and eventually overtakes the conspiracy theories.