Abigail Horn, 18, is charged with attempted homicide, aggravated assault, and endangering the welfare of a child, prosecutors wrote in a release.
Witnesses told Bethlehem police in May that they saw Horn "smothering" the then-6-week-old child, according to authorities. Others said Horn caused the baby to "scream and gasp for air," and on a separate occasion, "squeezed the infant and caused the infant to scream in apparent pain."
Photo evidence showed the baby suffered "bruising injuries," police said.
Court records show Horn was denied bail at her arraignment on Friday, July 26. She has a preliminary hearing set for Aug. 9.
Click here to follow Daily Voice Springfield Township and receive free news updates.