This is interesting to me.
I have been close to a number of people who suffered profound delusions. Are you asserting that their mental absurdities were actually things that happened IRL?
If so, that's a pretty unique worldview.
I mean, I'm glad to hear about your family being safe but that's frankly not a huge stretch of the imagination? Collectively the chances of it all happening are very slim, but that could be said about everything that happens in specific enough terms. A once-persecuted family having a thriving family tree isn't a unique or even unlikely result from that scenario. It's a story of familial peril and triumph, but not really one of defying the odds.
To reiterate what the parent was saying - there are degrees of delusion that range from "serendipitous coincidence" to "actual hallucinations caused by taking drugs". At some point along the line, surely all sane people would agree that delusion loses it's basis in rational thought...?