Nursing is mentioned the Bible a lot. There are stories connected to nursing and nursing is used as a metaphor. Here are some quotes:
Genesis 49:25-26 (Jacob speaking to his children on his death bed)
The God of your father, who helps you, God Almighty, who blesses you, with the blessings of the heavens above, the blessings of the abyss that crouches below, the blessings of breasts and womb, and the blessings of fresh grain and blossoms, the blessings of the everlasting mountains, the delights of the eternal hills. May they rest on the head of Joseph, on the brow of the prince among his brothers.
1 Kings 3: 20-21 (Harlot explaining to Solomon how another woman took her child)
Later that night she got up and took my son from my side, as I, your handmaid, was sleeping. Then she laid him in her bosom, after she had laid her dead child in my bosom. I rose in the morning to nurse my child, and I found him dead. But when I examined him in the morning light, I saw it was not the son who I had borne.
Job 3: 12 (Job lamenting that he was ever born)
Wherefore did the knees receive me? or why did I suck at the breasts?
Psalm 22: 10 (pleas of a person for God's aid)
Yet you drew me forth from the womb, made me safe at my mother's breast.
Psalm 131:2 (humble trust in God)
Rather, I have stilled my soul, hushed it like a weaned child. Like a weaned child on its mother's lap, so is my soul within me.
Isaiah 28:9 (prophetic warning)
To whom would he impart knowledge? To whom would he covey the message? To those just weaned from milk, those taken from the breast?
Isaiah 49:15 (some translations leave out the reference to the breast; how God will remember his people)
Can a mother forget her infant at her breast, be without tenderness for the child of her womb. Even should she forget, I will never forget you.
Isaiah 60: 16 (new Zion; does God say that he has breasts? hum.)
You shall suck the milk of nations, and be nursed at royal breasts; You shall know that I, the Lord, am your savior, your redeemer, the mighty one of Jacob.
Isaiah 66:11-12 (Zion suckling of Jerusalem)
Oh, that you may suck fully of the milk of her comfort, that you may nurse with delight at her abundant breasts! For thus says the Lord: Lo, I will spread prosperity over her like a river, and the wealth of the nations like an overflowing torrent. As nurslings, you shall be carried in her arms and fondled in her lap;
Joel 2: 16 (the day of the Lord)
Gather the people, notify the congregation; assemble the elders, gather the children and the infants at the breast; Let the bridegroom quit his room and the bride her chamber.
Luke 11: 27 (a woman blesses Mary)
While he (Jesus) was speaking, a woman from the crowd called out and said to him, "Blessed is the womb that carried you and the breasts at which you nursed."
Luke 23:29 (Jesus tells women to not mourn over his impending death)
for indeed, the days are coming when people will say "Blessed are the barren, the wombs that never bore and the breasts that never nursed."
People who are mentioned as nursing in the Bible: Sarah, Rebekah, Deborah, Moses's Mom, Hannah
Verses that mentioned an unidentified nurse (as in a person who nurses not a medical nurse): Numbers 11:12, 2 Samual 4:4, 2 Kings 11:2-3, 2 Chronicles 22:11
People who were weaned (very typical to have a feast and offerings after a child was weaned): Issac, Samuel, Lo-Ruhamah
So if anyone asks you why you are nursing in Church, I have armed you with the info. But for those who are Catholic here are some more reasons to nurse:
Oldest known painting of BVM depicts Mary nursing Jesus. The painting is located in the Priscilla catacombs.
Da Vinci and Michelangelo among many artists all depicted the Virgin Mary nursing Jesus.
The Mother of God Chaplet includes meditations on Mary's first nursing and her weaning of Jesus.
One of Mary's many names is Our Lady of Le Leche. This was the name the seven Catholic founders of Le Leche League took when starting their organization.
St. Bernard of Clairvaux (okay, friends and family. I'm not joking about that name) was said to have been praying to the BVM asking her to show that she had been a mother. The statute that he was before came to life and the BVM squirted breast milk on his lips. What a non-subtle way of saying she was a mom!
Also the BVM is said to feed the souls in purgatory her breast milk.
Patron Saints for Nursing: St. Basilissa and St. Giles
I hope that you enjoyed all this information as much as I enjoyed researching it for you.