Was the Blessed Virgin Mary An Unwed Mother?

No! The Blessed Virgin Mary was espoused to St. Joseph when she conceived our Lord by the power of the Holy Ghost, and per Jewish law, that espouse rite was when marriage was contracted. The Blessed Virgin Mary was married to St. Joseph and was not an unwed mother.

Father Gardner relates the following in a sermon from earlier this year which is quoted below:

Of all the weddings to contemplate, that of Mary and Joseph is the most special and rich in meaning.  The Espousals of Joseph and Mary have been celebrated as a feast day at various times throughout the history of the Church.

Pious tradition holds that Joseph was about thirty-three or thirty-six years old when he took Mary as his wife.  In those times, Jewish marriage was conducted in two stages.  First, the consent of the couple was obtained, a marriage contract was signed, and a wedding ring was given to the bride.

After this step, the couple continued to live apart so that they could adequately prepare for their married life together.  This period of preparation could last up to a year but was usually about three months.  At the end of the time of preparation, the husband would formally process to the bride's home and then the couple would formally process back to the groom's home, where a great celebration would take place.

The important point to remember is that in the ancient Jewish practice at the first betrothal the couple is more than just engaged.  They are validly married, yet their marriage is unconsummated.

Thus by God's providential arrangement, the Son of God became Incarnate in the womb of the Blessed Virgin Mary when Joseph and Mary were fully married.  Therefore, Jesus is a legitimate member of the Holy Family and the House of David, even though He was conceived before Joseph and Mary "had come together" (Matthew 1:18).