Of course on Hive many of us expect some effort and she is still learning about those expectations. She is coming from Facebook where people toss out just a photo and expect a load of likes

Like I said. The payout was not declined. The post was not published for likes but for rewards.
Facebook does not pay for posting.
Also, Just because Facebook is ridden with mass content theft/plagiarism, does not mean that the Hive ecosystem should be too.

Stealing is socially reprehensible. It's common, worldwide knowledge.
Try publishing plagiarism in University or any writers' type of website that pays for articles.
You would be banned/excluded permanently and potentially face legal consequences.
Also, any portals that have monetization for the content have strict rules about plagiarism and ban anyone who breaks these rules.

she is legally allowed to use

What does it have to do with anything if the content is public domain or free use?
Plagiarism is regardless if the content is free to use or not. Plagiarism is when the sources are not given. It is an attempt to deceive the readers that the author wrote the content while it was actually copied from a "free to use" website. The source was not given. If you wrote an essay in University and copied the text from Wikipedia without telling the teacher, you would be suspended. It is a fraud.

I ask once again.
Why do you think that you are entitled to get paid for plagiarism?
Why do you think that copying someone else's content and deceiving the Hive community about the authorship (by not giving the source or informing about the authorship) should be rewarded?

If you think that using free-to-use/public domain content without sourcing to exploit Hive should be accepted, then you are part of the problem.