No one can copyright an event
The events that happened to your father don't belong to anyone. They just are. Different people will have different knowledge (or beliefs) about various portions of the events, but they are just different versions of something that happened.
Yes, the author who published the story can copyright the book. But she is copyrighting her rendition of the story, not the events. Your father has the right to tell the same story in his own words. As do you. As does anyone.
Any legal issues are not about copyright
Copyright is not important here. Nor is it really a problem that this author took a real life story and turned it into a book. But using your father's name without his permission is a concern. Since it's a children's book (and you didn't mention this as an issue), I presume that she did not say anything negative about him or violate his privacy or anything like that.
At the very least, it's obnoxious to write a story about someone without his knowledge. Let alone his permission. Or that of his estate, if he is no longer living. Is it illegal? Probably not. After all, newspapers don't need permission to write about someone, why should children's books authors?
Ethically, she should have spoken to your family before moving ahead. And the publisher should have contacted you as well. It's strange that they didn't (unless she self-published). But, again, probably not illegal, as long as she didn't say anything untrue.
Ask a lawyer
To find out your rights, you need to contact a lawyer who works in your jurisdiction. This means in the country this happened in, or in the US state if it happened in the US. Even if I were a lawyer myself (I'm not) who knows publishing law backwards and forward, the law where I live could be completely different from the law where you live. So get a local expert. In the US, it should cost no more than a couple hundred dollars for a serious consultation (a quick consultation may even be free).