Well, I guess there are fewer people who get a kick out of literary analysis than I thought. So I'll give some answers to the questions I posed a few days ago (May 18, in the post "Happy Anniversary"--SEE BELOW) and let you all move on to other things.
But please do consider reading the poem once more--preferably out loud--and savoring it, especially after you've read my explanations.
(1) Kind of poem: Sonnet (14 lines--was invented about 700 years ago in Italy, first came into English about 500 years ago)
(2) Kind of sonnet: Italian or Petrarchan (yes, there are several kinds of sonnets, Italian or Petrarchan being the original version invented by Petrarch in the 1300s; the English invented another rhyme scheme, called the English or Shakespearean sonnet, though it was used a couple of decades before Shakespeare was born; and then in the 1590s, Edmund Spenser invented the Spenserian sonnet). All sonnets can be said to have an octave (8 lines) and a sestet (6 lines), but the division between the two is more prominent in the Italian or Petrarchan version. The rhyme scheme is the real giveaway: normally, abba abba followed by six lines with some combination of two or three rhymes (e.g., cddcee, cdecde, cdcdcd, etc.), but in the case of the one I've written, abb'a' a''b'ba''' cded'ce' (the apostrophes after some of the letters mean that these are "off rhymes"--meaning not very exact at all--so this is a "modernish" poem).
(3) Quotations: The first two lines are paraphrased from A Grief Observed (C. S. Lewis) and refer to his wife, Helen Joy Davidman Gresham Lewis, who had just died of cancer. The book is the published form of the heart-wrenching diary he wrote after her death. His actual lines: "Her mind was lithe and quick and muscular as a leopard." She "was a splendid thing; a soul straight, bright, and tempered like a sword." "I see I've described [her] as being like a sword. That's true as far as it goes. But utterly inadequate by itself, and misleading. . . . I ought to have said, 'But also like a garden. Like a nest of gardens, wall within wall, hedge within hedge, more secret, more full of fragrant and fertile life, the further you entered.'"
"Mine own, yet not mine own" is Shakespearean, from A Midsummer Night's Dream. It's said by one of the young lovers when they all wake up after a night in the woods and finally find they're all in love with the right person. I've always felt the line marvelously evokes the sense of belonging yet also of otherness, even strangeness, that comes with an intimate relationship. I am intimately connected, in some ways even merge, with my beloved. Yet that connection somehow makes me even more aware of how absolutely unique and independent, in some essential way, each of us is. As Levinas puts it, the other person "escapes my grasp by an essential dimension, even if I have him at my disposal." And in the case of love--if it is genuine (genuinely respectful and caring)--I am very careful about even seeking to have her at my disposal and in fact want more to be at her disposal. Paradoxically, or miraculously, I can in some sense "possess" her (or be possessed by her) while still respecting her agency and her otherness.
(4) Jack and Joy: No, not from a nursery rhyme (that would be Jack and Jill?). Rather, C. S. Lewis and his wife. She went by "Joy"; he went by "Jack." Though the "C. S." stands for "Clive Staples," one day (age 8, I believe) he announced, "My name is Jacksie," and he was known to friends and family as "Jacksie" or "Jack" from that point on.
(5) Other allusions: Besides the Levinasian overtones in "Mine own, yet not mine own," there's more Levinas in the phrase "your real and complete otherness." But that phrase also echoes Lewis (this is a point of convergence between Lewis and Levinas). In A Grief Observed Lewis says: "The most precious gift that marriage gave me was this constant impact of something very close and intimate yet all the time unmistakably other, resistant--in a word, real." And then he applies this thought to God and to people in general, reminding himself he must never confuse his image or idea of someone with the real "someone" who is other than and outside of himself and who cannot be reduced to an image or idea: "I need Christ, not something that resembles Him. I want [my wife], not something that is like her. . . . Not my idea of God, but God. Not my idea of [my wife], but [my wife]. Yes, and also not my idea of my neighbour, but my neighbour." For "All reality," he says, "is iconoclastic"--that is, it breaks apart the images we have created as a kind of subsitute. "The earthly beloved, even in this life, incessantly triumphs over your mere idea of her. And you want her to; you want her with all her resistances, all her faults, all her unexpectedness. That is, in her foursquare and independent reality."
That (from Lewis) sounds very Levinasian. Compare, for instance, this from Levinas in Totality and Infinity: the Other, in his expression, "at each instant he overflows the idea a thought would carry away from it"; "The face of the Other at each moment destroys and overflows the plastic image it leaves me. . . . The face is a living presence; it is expression. The life of expression consists in undoing the form in which the existent, exposed as a theme, is thereby dissimulated. . . . This way of undoing the form adequate to the Same [that is, to my self-contained consciousness] so as to present oneself as other is to signify or to have a meaning." (I believe this is all on pages 50-51 and 66--for those of you who want to read the passages in context and figure out exactly what Levinas is saying.)
One more thing: "many selves" refers to the seven nouns in the last two lines of the poem--that is, Margaret's many roles, many ways of being and doing, contained within one unique and eternal self. For the eternal dimension of selfhood, see Doctrine and Covenants 93:29 and the King Follett discourse. And for "queen and goddess," see Revelation 1:6, 5:10, 21:7, D&C 76:56-60, 132:20, Romans 8:17, John 1:12, 10:34, 1 John 3:2, 2 Peter 1:4, and several passages in Lewis's writings.