fair use

• https://copyright.columbia.edu/basics/fair-use.html

• Factor 1: The Purpose and Character of the Use

  • Did the author attribute your daughter's work as "from the internet", or directly present as the author's own word? 

• Factor 2: The Nature of the Copyrighted Work

  • What is your daughter's article?  see factor 4 as well. 

• Factor 3: The Amount or Substantiality of the Portion Used

  • How many words/paragraphs are used?  

• Factor 4: The Effect of the Use on the Potential Market for or Value of the Work

  • Was your daughter's article freely avalable?  what's her damage on being copied?  

The issue might lie in "attribution" instead of copyright infringment.  The author's proposal "以后会加她的名字或改掉。"  is reasonable.  

Since this publisher is a big house, most copyright firms might have business with the publisher so that's why their lawyers cannot help your daughter.  If fact I think most major copyright law firms might have business with this publisher.  You need to dig deep to find small or medium sized copyright firms in NY.