In today’s text, Mary and Elizabeth greet one another and spend some time together. At this time, Elizabeth has been pregnant for about 6 months, and Mary is probably just a few weeks along in her pregnancy. Elizabeth blesses Mary and her child, and Mary recognizes her own blessedness for being chosen to be the mother of the Messiah. So it seems that blessing or happiness is a major theme of the passage.
The second part of this section (vss. 48-55 is often called “the Magnificat” because in the Latin text, the opening word is “Magnificat,” meaning, “magnifies/glorifies.” (Magnificat anima mea Dominum—“my soul magnifies the Lord”)