Not quite. As Fred pointed out Ellen White denied using the writings of others the way she did. She said that everything she published was “fresh and new”. James wrote that her writings were entirely different from anyone’s because she knew things that nobody else did.
She and James went to a health farm and began writing her health message immediately afterwards. When people remarked about the astonishing similarity in her books and the proprietor’s, she expressed surprise because , as she explained, she and her husband had skipped all of the lectures because of James poor health. She had bought all of the host’s health books, but didn’t open any of them until after she finished her writings on his subjects. [Isn’t that amazing!]
She reported the same thing about Lucifer’s [sic] fall in _Paradise Lost_to keep people from suspecting she borrowed again. (It didn’t work.)