I've just heard the best story in the world. For those of you who know Ada, this will totally make sense. For those of you who don't know Ada, you should.
When Ada's mother was giving birth to her (back in the 20s), she noticed that one of the nurses was crying. When she asked what was wrong, the nurse said that she had just found out that her sister in Ireland had died.
Ada's mother asked the nurse what her sister's name was, and said that if her child was a girl, that was what she would name her. It was, which is how Ada got her name.
Oh man. Still a bit sniffly after that one.