Board Thread:Questions and Answers/@comment-918732-20160414170412/@comment-918732-20160421180949

Just a short primer:

On Earth-One, Thelma Gordon was the wife of Commissioner Jim Gordon and the mother of Tony Gordon and Barbara Gordon. She died when Tony and Barbara were young (but we don't know exactly when).

On New Earth, Thelma Gordon was the wife of Roger Gordon, sister-in-law of Commissioner Jim Gordon and mother of Barbara Gordon. She (and Roger) died when Barbara was thirteen, and Jim and his wife (also named Barbara) adopted Barbara.