She is the daughter of Etam and sister of Ishma. Barren and childless, Samson's mother is startled when an Angel of the Lord appears to her an announces the forthcoming birth of her and Manoah's son.
Both she and Elizabeth were mothers of “nazarites:” men set apart by God before birth as holy men.

She was known for her goodness in heart and deeds. She was a mutual bread-winner with her husband. Samson’s wonderful mother, more than most women in the Scriptures, fits the picture of the ideal wife drawn by the wiseman at the close of his book (Proverbs 31:10-31). Because, like Elizabeth and Mary, she was the mother of a son whose birth was announced by God. Samson’s mother’s story (Judges 13) Why is Samson’s mother the mystery woman of Advent? Samson's mother is the wife of Manoah and, like her husband, is an actual historical personage from Judeo-Christian scripture.

Mother of Samson: Bible by J. Cheryl Exum Here no background is offered—whether like Sarah the woman was old, or like Rachel she complained to her husband about childlessness, or like Sarah and Rachel she tried other means of obtaining a child.