Maureen is RR's natural born child...........she wanted a brother
RR and Jane Wyman adopted a son, Michael.
Jane Wyman left RR to pursue Hollywood career, RR met and married Nancy.
Nancy and RR have Patty, then Ron P. Reagan.
ALL FOUR children are RWR's children. Period.
Also, just recently read that they actually had a natural born child after they adopted Michael but he died a day later.