Advice needed re: relationships
What is the best way to enter the data for the following situation:
Dick and Mary raised six children: Michael, Sheila, Robert, John, Dick, Jr., and Susan. Mary was identified and raised all the children as her own. Turns out she was the birth mother to only Michael, Robert, and Susan. The birth mother to Sheila, John, and Dick, Jr. was Mary's sister Helen. How do I enter this in the family tree???