How many times in Scripture is God referred to as Mother?

Answer 1

Never. However, you may be confusing a Scripture in Galatians 4:26 seen here (speaking of the New Jerusalem in Hebrews 12:22-23; Revelation 21:19-20):

Galatians 4:26

New International Version (NIV)

26 But the Jerusalem that is above is free, and she is our mother.

In Galatians, Paul is using the common 'allegorical method' of the day to make his point (see verse 4:24 and the term 'symbolic). Paul uses this approach to draw a stark distinction between the two biblical covenants that were at odds with each other in the churches in Galatia - the Abrahamic promise (Genesis 12:1-3) and the Law of Moses that God gave all Israel at Mount Sinai. Paul compares Jerusalem - the center of Jewish life, to Mount Sinai - the birthplace of the Law of Moses.

The Jerusalem above (New Jerusalem) represents the hope of the Jews of heaven finally coming to Earth (see Revelation 21:22). The 'mother of us all' refers to those who are free through faith in Christ as Paul noted earlier in verse 7 of this chapter. The question Paul was asking the Galatians was are they shortsighted and willing to follow the Jerusalem of legalism in the present or the liberty of the heavenly Jerusalem that is promised to come. Paul uses Isaiah 54:1 to illustrate how the latter would outnumber the earlier offspring.