Here is one thing we can take to the bank pertaining to teachings outside of Ellen authorized materials.
James White ( Ellen's husband )
"We invite all to compare THE TESTIMONIES of the Holy Spirit THROUGH Mrs. White with the word of God. And in this we do not invite you to compare them with your creed. That is quite another thing. The TRINITARIAN may compare them with his creed, and because THEY DO NOT AGREE WITH IT, CONDEMN them [ the testimonies of Mrs. White ]. The Adventist Review & Sabbath Herald June 13, 1871
The Bible can be muddy according to Ellen White.
The Bible is written by inspired men, but it is NOT God's mode of thought and expression. It is that of humanity. God, as a writer, is NOT represented. Men will often say such an expression is not like God. But God has not put Himself in words, in logic, in rhetoric, on trial in the Bible. The writers of the Bible were God's penmen, NOT His pen." (Selected Messages, Vol. 1, Chapter One "The Inspiration of the Prophetic Writers")
Ellen however DID represent God, word for word.
After the passing of the time in 1844 we searched for the truth as for hidden treasure. I met with the brethren, and we studied and prayed earnestly... When they came to the point in their study where they said, "We can do nothing more," the Spirit of the Lord would come upon ME. I would be taken off in vision, and a clear explanation of the passages we had been studying would be given ME, with instruction as to how WE were to labor and teach effectively. Thus light was given that helped us to understand the scriptures in regard to Christ, his mission, and his priesthood. A line of truth extending from that time to the time when we shall enter the city of God, was made plain to ME, and I gave to others the instruction that the Lord had given ME." (Review and Herald, May 25, 1905)