That's true.
That's false.
What Dedra pitched was the idea of Ghorman rebels to generate sympathy for the Empire so that there would be public approval for a crackdown on Ghorman. Partagaz confirmed to her that that had worked.
When Dedra asked Partagaz for clarity on what exactly she was to do once the mining equipment was being set up and the armory barricading had begun, Partagaz told her that she did not need to concern herself and that Captain Kaido would handle matters at his discretion. Dedra did not know who Kaido was, she was not told in advance that he was coming, nor did she have knowledge of his operational plans. They were quite specific about these points on numerous occasions. All Dedra was to do was give Kaido the order to proceed, and once she did that, everything would be handled by Kaido.
It would have been consistent with what Dedra pitched to Krennic for the Ghorman rebels to rise up and kill Imperials.
However, there was never any evidence presented at any time that having Imperial special snipers shoot regular Imperial troops was Dedra's idea, nor was there any evidence that she approved of this action. Once Dedra saw the set-up, when the time came for her to relay the order for Kaido to put his plan into motion, she hesitated, although as I've opined before, she had no practical alternative except to rubber-stamp the operation, as was expected of her.
What happened in the plaza was neither planned nor proposed by Dedra.