She may not have SZ - depression, PTSD, even severe anxiety can cause psychosis.
But, she's paranoid & delusional - so just stick with psychosis instead of worrying about whether or not she has SZ.
My favorite book for this kind of thing is I'm Not Sick, I Don't Need Help by Dr Xaviar Amador. There are also videos on Youtube, he has a website & there are links here.
It goes over methods that help you talk to someone who lacks insight (doesn't think they're sick) and helps you find common ground so you can convince them to get help even if they don't ever see that they have lost touch with reality.
If she admits she had PTSD, that's your open door. If not, maybe you can talk to her about getting some help with her anxiety or something to help her sleep better.
My son, when he was first psychotic, thought government agents would knock down the door at any moment to kill him because he "knew" something. Of course, he can't tell us, because it would put us in danger.
He's past that, but now, he believes he knows & talks to all kinds of celebrities - so everything you're talking about is common with psychosis.
If you ever feel that the children are in danger, that would also be a time to act.
If she gets to the point that she's gravely disabled & can't protect herself from harm, that can get an involuntary hospitalization too. Not being able to protect yourself includes all kinds of things from not eating to standing in the middle of traffic. Learn the law where you live & get someone to explain everything that you can use - not the police, but a crisis line or something like that.