Joseph Bassett … m. (1) by about 1660 Mary _____ (said to be his stepsister Mary Lapham, daughter of Thomas Lapham [see NEHGR 115:85].
… the daughter Mary (Lapham) may have married her stepbrother, Joseph Bassett.
1658 Mr. John McIlvene of Northampton, a very keen Bassett historian, was almost certain that Joseph Bassett married (1) about this year his step sister Mary Lapham. If so he was now 23 while she was about 17.