Here's the story as I've heard it from my grandmother who got it from her mother.
Birdie P. ran off and Married Earl Finley McGrew. Mr. McGrew's family had money and brought the two back and had the marriage annulled. Of course by this time Birdie was pregnant. Birdie married E. Grant Curtis (my great granfather) by the time Coral was 6 months and I believe he raised Coral as his own (although no official adoption).
Birdie P. then had a mess more kids. As she did more and more of what she wanted (eventually leaving the kids and hooking up with Alton Cooper), Grant sent Aunt Neva to live with first his brother Gene & Lizzie Curtis and then Ed & Ruby Curtis. Grant sent Aunt Hilda to live with Aunt Pearl & Uncle Dave Eschliman.