I know that Kathleen Hite was a very good researcher, especially when it came to writing episodes that feature a woman as the emphasized character. I can't really add to what's been written already.
But there is one glaring error that is brought up between Lacey and Jess, and again between Lacey and the Marshal. Jess had told Lacey before her Pa was shot dead (all off-screen) that no woman had been hanged. Later, Lacey asks Matt if he'd ever seen a woman hanged. Matt say he hasn't.
While probably an accurate statement on its own, Dillon probably did read about a woman who had been hanged in the previous decade prior to when Gunsmoke was set. It was the hanging of Mary Surratt in 1865 of being involved in the conspiracy to assassinate Abraham Lincoln. She owned the boarding house where John Wilkes Booth met with Mrs. Surratt's son and the other co-conspirators. She and three others were hanged at the same time less than 3 months after Lincoln's murder.
Ironically, Mrs. Surratt's son was eventually tried in a civilian court, and after a hung jury, a mistrial was declared. Although he admitted to the kidnapping part of the plot, he never admitted to being a part of Lincoln's assassination. He lived into the 20th Century.