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
References
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