Thanks! You’re too kind.
The odds are heavily against me finding anything conclusive. I’ve spend just a bit of time searching the word “Sheila” mixed in various combinations with words like:
Obama, Chicago, Community Organizer Cynthia Norris, Holy Rosary, Bill Ayers University Illinois
Adding in “born 1960 1961 1962 1963” might narrow it down a lot to Sheila candidates near his age...