Origins

Daughter of Abigail Horton and Theodore Horton, sister of Theodore Horton, Junior and wife of Sir Gerrold Sinclair. Dated Oliver Queen, before he became Green Arrow.

Creation

Cynthia was created by Dick Giordano, Mike W. Barr and Trevor Von Eeden for their mini-series Green Arrow.

Major Story Arc

Green Arrows

Years ago, before Oliver Queen became the Green Arrow, Oliver and Cynthia's mother, Abigail Horton were close friends. This was how Cynthia and Oliver met and started dating. The pair didn't last long, as the two of them had nothing in common. Oliver left and became Green Arrow and didn't see Cynthia again for years. In that time Cynthia had married Gerrold Sinclair and had become a ruthless businesswoman.

Then Cynthia sees Oliver at Abigail's will reading and tries to rub it in that she is happy, but Oliver could care less, he is more concerned about Cynthia's mother, then Cynthia is. Then when it is revealed that Oliver is inheriting the Horton family fortune, Cynthia is shocked just like the rest of the family.

Later it is revealed that Gerrold was the one that murdered Abigail, and when Green Arrow arrives to arrest him, he finds the man dead, from a gunshot to the temple. Cynthia reveals that it was who mastermind the murder of her mother, and took out Gerrold, as the only living witness.

It looks like Cynthia, who knows Green Arrow's secret identity is about to shoot the hero, but in a strange twist of fate, Gerrold isn't quite dead yet and is able to shoot and kill Cynthia with his dying breath.