If Sarah Weeden’s dates are anything like right, most likely Rebecca was her only child with Peter.


From D. Pane-Joyce’s website on the Pane-Joyce Genealogy:
Analysis of names. Although it's often mentioned that Peter is the son of Rafe and Grace (Neal) Mallory, that's unlikely. Rafe and Grace apparently had children named Francis, Thomas, Matthias, and Anne, none of Peter's children or grandchildren are named Rafe, Grace, Francis, or Mathias. One son is named Thomas, and the only grandchildren named Anne are named after a mother or grandmother. Furthermore, the eldest sons and daughters of Peter's children Peter, Thomas, John, Joseph, and Rebecca are all named after their parents, and later children of Peter's children Mary and William are named after their parents. Also, two of Peter's grandsons (besides his son Peter's son) are named Peter, and one of his granddaughters (besides his daughter Mary's daughter) are named Mary. Among the names common to Peter's children and grandchildren that are unnaccounted for are John, Daniel, Benjamin, Rebecca, Judith, and Abigail.799