Belladonna Took, later Belladonna Baggins, was the mother of Bilbo Baggins and wife to Bungo Baggins.1, 2 Along with nine brothers and two sisters, she was a daughter of the Old Took (Gerontius Took).1
Being a Took, she was prone to adventures, but she settled down after marrying Bungo Baggins.2
They had one son, Bilbo, who was born in T.A. 2890.1
Bungo built Bag End for her and she lived there until her death in T.A. 2934.1, 2
1 - J.R.R. Tolkien, The Lord of the Rings, Appendix C, "Took of Great Smials"
2 - J.R.R. Tolkien, The Hobbit, An Unexpected Party