You are thinking of Anne. She is the young woman who had the miscarriage that Bethia Mayfield helped deliver. The controversy over that baby is how far along the pregnancy was. Bethia is very confident that Anne was further along in the pregnancy than the midwife, Goody Branch, says she was. If Bethia is right, then she was pregnant before she arrived at Cambridge and the scandal of her pregnancy has no touch on the young men at the school, but Branch claims the fetus is smaller, and that puts the affair to have taken place at Cambridge where she could be subject to public humiliation and punishment by whipping. Anne refuses to the end to admits who the father of the baby was, and is ultimately saved by Bethia who arranges to send her off to the Island.
Correction from Alicia: The Native American woman's name was just "Anne." Anne Bradstreet was New England's first woman poet whose poem "To My Loving Husband" Bethia liked. Apologies for the error!
Goody Branch was midwife for Bethia's mother. Goody Marsden was midwife for Anne Bradstreet, who married Joel Iacoomis.