For comparison to the bourgeois context of Margery Kempe, see writings of a well-educated abbess of the 12^th century. Hildegard of Bingen  (1098-1179)  was a composer as well as author of books on medicine and spiritual treatises. She was a visionary and described the visions and her purpose in the introduction to her book Scivias. See this text and a letter on her visions and authority in English translations by Abigail Ann Young, University of Toronto. http://www.chass.utoronto.ca/~young/trnintro.html 
 See also information on Hildegard and "science" under the medieval view of nature.  

The Vision of the Trinity Scivias: Book II/ Vision 2 

Then I saw a bright light, and in this bright light the figure of a man the color of a sapphire, which was all blazing with gentle glowing fire. And that bright light bathed the whole of the glowing fire, and the glowing fire bathed the bright light; and the glowing fire poured over the whole human figure, so that the three were one light in one power of potential. And again I heard the living Light say to me: "This is the perception of God's mysteries. . . . 

Therefore you see a bright light, which without any flaw of illusion deficiency or deception designates the Father; and in this light the figure of a man the color of sapphire, which without any flaw of obstinacy, envy or iniquity designates the Son, Who was begotten of the Father in Divinity before time began, and then within time was incarnate in the world in Humanity; which is all blazing with a gentle glowing fire, which fire without any flaw of aridity, mortality or darkness designates the Holy Spirit, by Whom the Only-begotten of God was conceived in the flesh and born of the Virgin within time and poured the true light into the world. And that bright light bathes the whole of the glowing fire, and the glowing fire bathes the bright light: and the bright light and the glowing fire pour over the whole human figure so that the three are one light in one power of potential. 

And this means that the Father, Who is Justice, is not without the Son or the Holy Spirit; and that the Father, Who is Justice, is not without the Son or the Holy Spirit; and the Holy Spirit who kindles the hearts of the faithful, is not without the Father and the Son; and the Son, Who is the plenitude of fruition, is not without the Father or the Holy Spirit. They are inseparable in Divine Majesty, for the Father is not without the Son, not the Son without the Father, not the Father and the Son without the Holy Spirit, nor the Holy Spirit without them. Thus these three Persons are one God in the one and perfect divinity if majesty, and the unity of Their divinity is unbreakable; the Divinity cannot be rent asunder, for it remains unstable without change. But the Father is declared through the Son, the Son through Creation, and the Holy Spirit through the Son incarnate. How? It is the Father Who begot the Son before the ages; the Son through Whom all things were made by the Father when creatures were created; and the Holy Spirit Who, in the likeness of a dove, appeared at the baptism of the Son of God before the end of time. Hildegard of Bingen, Scivias. trans. Mother Columbia Hart and Jane Bishop. Paulist Press. Mahwah, NJ. 1990, pp. 161-62. 
 

SOURCES: Hildegard of Bingen, Scivias. trans. Mother Columbia Hart and Jane Bishop. Paulist Press. Mahwah, NJ. 1990.