The First Lady of the Church is the Church itself, and her duties are:
1) Be our Mother - Galatians 4.26
2) Be our bride - Revelation 21.2
3) Be subject to Christ - Ephesians 5.24
If you are thinking of the Christian church, that honor would go to Mary, the mother of Jesus Christ.
In terms of the people in the church the first lady is usually the pastors wife - unless you're Catholic! ;)
Some Baptist churchs refer to the pastor's wife as the first lady.
Most likely the pastors wife.
Get married to the pastor
Our Lady of Lourdes Church was created in 1923.
Church of Our Lady of Loreto was created in 1642.
Our Lady of Egypt Church was created in 1606.
Church of Our Lady of Springs was created in 1506.
Church of Our Lady - Copenhagen - was created in 1829.
Church of Our Lady of Esperanza was created in 1912.
Our Lady of the Wayside Church was created in 1912.
Church of Our Lady before Týn was created in 1511.
Our Lady of Mount Carmel Church was created in 1913.
Our Lady Of Victory Church - Inuvik - was created in 1960.
Our Lady of Victories Parish Church was created in 1580.