Eliza R. Snow holds a unique position in Mormon history. She never had children or a husband of her "own," though she was married to the first two LDS Prophets. Eliza became extremely influential in the early Church for a variety of reasons. Her situation with less family responsibility gave her free time to pursue her interests. Her calling as General Relief Society President saw her travelling among the Saints and gave her an authoritative position. Her proximity to Church leadership put her in firsthand touch with Church doctrine as it was developed. Finally, her considerable talent in writing gave her a voice among men and women alike.
We are all aware of Eliza's contribution to LDS belief through her poem, "The Eternal Father and Mother," which became the popular hymn "O My Father." The poem was frequently reprinted, put to a number of musical settings, and sung at formal as well as informal Church settings. Eliza popularized the concept of a mother God to such an extent that by 1873 Wilford Woodruff credited her poem as the source of the doctrine, identifying it as "a revelation, though it was given unto us by a woman--Sister Snow." 
The female bard Eliza treated many other principles of the Church in her poetry. One of her lesser-known poems, "The Ultimatum of a Human Life"  is of interest because it speaks of the Adam-God doctrine, once furiously debated, and now repudiated in the modern Church. "The Ultimatum" begins in a familiar LDS setting. The author is musing at twilight when a spirit guide appears to instruct her. This scene vividly recalls Lehi's dream in the Book of Mormon. Lehi's son Nephi likewise had the experience of entertaining an angel who had come to instruct him in religious principles. To a Mormon audience, this poetic convention gives the later instruction a powerful endorsement.
"What would'st thou me?" the seraph gently said:
"Tell me, and wherefore hast thou sought my aid?"
The author asks her spirit guide to explain the cause of suffering upon this earth and what will be the end result of human life--"its ultimatum in Eternity." The angel tells her that it is not necessary for her to know the secrets of the worlds on high, the Councils, decrees, organizations, laws formed by the Gods on high. These took place before her great Father came forth from their great courts to tread upon this new world and stand as it's royal head. Instead, the angel explains to her the ordeal and purpose of life. But in various places in the poem we learn more about this behind-the-scenes view of Eternity:
Adam, your God, like you on earth, has been
Subject to sorrow in a world of sin:
Through long gradation he arose to be
Cloth'd with the Godhead's might and majesty...
By his obedience he obtain'd the place
Of God and Father of this human race.
A second poem written by Eliza, "We Believe in Our God," was also included in the LDS collection of hymns until the year 1912. This poem described God as the "prince of his race," and identified him simultaneously as Adam, the Ancient of Days, and Michael the archangel.
We believe in our God, the Prince of his race,
The archangel Michael, the Ancient of Days
Our own Father Adam, earth's Lord as is plain,
Who'll counsel and fight for His children again.
We believe in His Son, Jesus Christ who in love
To His brothers and sisters came down from above,
To die, to redeem them from death, and to teach
To mortals and spirits the gospel we preach. 
In another poem, titled "To Mrs. ___ ," Eliza combines Adam-God with the couplet theology of godhood originated by her brother Lorenzo Snow:
...But now I’m but a child of dust;
Thanks, thanks to Him, in whom I trust,
I’m not without his wise direction,
His smiles, his guidance and protection.
Adam, our father--Eve, our mother,
And Jesus Christ, our elder brother,
Are to my understanding shown:
My heart responds, they are my own.
Perfection lifts them far from me,
But what they are, we yet may be,
If we, tho’ slowly, follow on,
We’ll reach the point to which they’ve gone. 
Clearly Eliza R. Snow agreed with and sought to promote the Adam-God doctrine preached by Brigham Young. Because acceptance of Adam as our Father and God implies Eve as our Heavenly Mother, some have connected this theory with the equally speculative Mother in Heaven axiom.  Why was the Heavenly Mother so readily absorbed into Mormon thought while Adam-God has died an ignomonious death? Joseph Smith and Brigham Young defended the concept of speculation, pondering, theorizing, and seeking the mysteries far more than is common today. Thus there were several speculative ideas preached by early Church leaders which were later refined or rejected outright by their successors. Van Hale has pointed out that Brigham Young said that his views were not official doctrine, nor mandatory for the Saints to believe.  Brigham and his prime supporter on Adam-God, Wilford Woodruff, experienced great opposition among their colleagues in the Twelve concerning the idea.  On the other hand, the Heavenly Mother idea was comforting, non-threatening and widely accepted. Every latter-day prophet has reaffirmed the existence of a Mother in Heaven. Indeed, the teaching has probably been challenged more in the past 5 years than in the 163 years since it was penned.
 Wilford Woodruff quoted in Jill Mulvay Derr, "The Significance of 'O My Father' in the Personal Journey of Eliza R. Snow," BYU Studies 36:85-126.
 "Poems, Religious, Historical, and Political by Eliza R(oxy) Snow. Vol. II, Compiled by the Author," Latter-day Saints' Printing and Publishing Establishment, 1877, 5-10; http://www.celestial-orb.com/ultimatum.htm .
 Sacred Hymns and Spiritual Songs for the Church of Jesus Christ of Latter-day Saints, 11th Edition, revised in Liverpool, 1856, by Franklin D. Richards, Apostle; p. 375. See also the 25th edition, 1912.
 citation needed
 Blake Ostler has opined, "I view the notion of the mother in heaven as originating in a cultural overbelief (a mere ball that got rolling with a misunderstanding of an authoritative statement), was first elucidated as part of BY’s and Eliza’s Adam God doctrine, and then got baptized by Joseph F. Smith." Comment #10 at New Cool Thang blog. http://www.newcoolthang.com/index.php/2006/06/spirit-birth/258/
 "[The] subject ... does not immediately concern yours or my welfare ... I do not pretend to say that the items of doctrine and ideas I shall advance are necessary for the people to know." (Brigham Young, Historical Department of the Church [HDC], Oct 8, 1854). See this and other statements in "What About the Adam-God Theory?" by Van Hale at http://www.lightplanet.com/response/adam-god.htm
 Including, most notably, Orson Pratt. Brigham allowed Orson his judgment on the matter and gave him the freedom to express his opinions publicly without sanction or punishment.