vs 26 "The sixth month", at first the meaning is ambiguous. Did he mean the 6th month of the Jewish Civil Calendar, which is Feb-Mar, or the 6th month of the Jewish Sacred Calendar, which is Aug-Sept, or was he referencing Elizabeth being in her 6th month after conceiving John the Baptist (note Luke 1:36)? Most likely the latter for note a couple of verses previous to this Luke 1:24 "Now after those days his wife Elizabeth conceived; and she hid herself five months" ... "In the sixth month".

The angel Gabriel had previously spoken to Zacharias in Luke 1:19, so again we see the continuity. The only other place he shows up is in Daniel 8:16 and 9:21 where God said, "Gabriel, make this man understand the vision." and again in 9:22 Gabriel himself said, "O Daniel, I have now come forth to give you skill to understand." So it seems his function is primarily that of imparting understanding to people.

Those from Galilee were looked down upon much as people speak of those on the "other side of the tracks". Galilee was separated from Judaea by Samaria (the tracks). Of Nazareth in particular it was said rhetorically, "Can anything good come out of Nazareth?" John 1:46 This fact along side Mary's later reference to her lowly state speaks of God's focus on the lowly, the outcast, the despised, as also will be evident regarding the state of his son, his life, ministry focus and death. The gospel is not for the proud but for the humble.

vs 27 "pledged to be married" This is not simply referring to an engagement. Rather they are married but have yet to consummate the marriage.  We note that upon hearing of her pregnancy Joseph "he had in mind to divorce her quietly" Mt 1:19 Therefore they must have been legally married. And furthermore Matthew clarifies, "Mary was pledged to be married to Joseph, but before they came together..." (referring to sex) This also implies, contrary to Catholicism, that Mary was only a virgin until after Jesus was born. And what would be the point of marriage if sex wasn't a part of it?  Both Joseph and Mary were descendants of David. See my article on Jesus' Genealogy. The name Mary or Miriam in Hebrew means "their rebellion" referring to the rebellion of  Aaron and Miriam who is the sister of Aaron and Moses. "Then Miriam and Aaron spoke against Moses because of the Ethiopian woman whom he had married; for he had married an Ethiopian woman. So they said, "Has the LORD indeed spoken only through Moses? Has He not spoken through us also?" And the LORD heard it." Nu 12:1,2 Miriam ended up getting leprosy as a result. (Seems familiarity breeds contempt, which later in the gospels I would argue reveals that in Mary as well)

vs 28 The phrase "Greetings, you who are highly favored! The Lord is with you." is the basis of the Catholic mantra "Hail Mary full of grace". Though "full of grace" is a misreading of the word. There is a variant reading found in the KJV (based on the Textus Receptus) not found in modern versions which continues, "blessed are you among women!". But it is found in all versions in verse 42 where Elizabeth declares "Blessed are you among women, and blessed is the fruit of your womb!" So completes the Catholic mantra.

"Greetings" is more accurately "Rejoice" <5463>.

"Highly favored" is the perfect tense "Have up to this point been highly favored". And it is not unique as this Greek word <5487> for "highly favored" is used regarding all believers in Eph 1:6  "to the praise of the glory of His grace, by which He has made <5487> us accepted <5487> in the Beloved". One could translate as "He has highly favored us in the Beloved". Mary was one of the many who were highly favored. Believers are highly favored by God. And God wants us to be happy about that fact.

"The Lord is with you" speaks not only of His favor, but his presence. And quite literally so in the case of Mary. And likewise of believers of whom it is said that Christ lives in us. Eternal life is a relationship with God. I suspect there are many who would like to go to heaven as long as God is not there.  God being with us gives us the courage and perspective to live life contrary to the world, which would be the case with Mary's pregnancy.

vs 29,30 As the angel told her not to be afraid, apparently Mary's troubled reaction was due to fear, which is typical of many in the scriptures confronted by angels. Realize that "do not be afraid" is not simply a word of encouragement. It's actually a command. It's in the imperative. And there are many such commands throughout scripture to not be afraid. "Have I not commanded you? Be strong and courageous. Do not be terrified; do not be discouraged, for the LORD your God will be with you wherever you go." Jos 1:8 To worry or be afraid is to be disobedient, if it's not followed by a prayer which results in you relinquishing your fears. "Do not be anxious about anything, but in everything, by prayer and petition, with thanksgiving, present your requests to God.  And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus." Php 4:6,7 Even Jesus practice such in Gethsemane.

"You have found" is in the active voice, indicating that which she did, resulting in grace from God, much like it's written in Jer 29:13  "And you will seek Me and find Me, when you search for Me with all your heart." When  one realizes that they're in God's grace, his perfect love for us relieves all fears. "There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love." 1John 4:18 

vs 31 The name "Jesus" or its Hebrew origin "Joshua" means "Jehovah is salvation". The parallel verse in Mark 1:21 says, "you shall call His name JESUS, for He will save His people from their sins."
 
vs 32,33 Jesus' role is not simply to save, but to reign. It's a kingdom, not a democracy. Jesus is not to be viewed as simply a fireman coming to rescue people from the fire. For a fireman, after having rescued people doesn't demand they accept him as the Lord of their life.  While there will be many sons of God. Jesus is the Par Excellence Son of God. That is "The" Son of God. It was understood even by Jewish unbelievers that the Messiah is the Son of God.

The high priest said to him, "I charge you under oath by the living God: Tell us if you are the Christ, the Son of God."  "Yes, it is as you say," Jesus replied. Mt 26:63,64

The Messiah was also to be "The" Par Excellence son of David, who was promised rulership over the kingdom.