No one talks about the sacrifice of Lyra Erso (Jyn’s mother) in Rogue One, and I am worried that it is because they think her character was thrown away, or that she was foolish or reckless. Allow me to assure you that this is not the case.
The companion novel Catalyst focuses heavily on Lyra and her respect for the Force. She is determined, penitent, and clever–hardly someone who would throw her life away in a half-baked assassination attempt.
She would, however, allow herself to be killed if she knew it was a winning move.
Lyra knew that Galen couldn’t lie about her being dead because the evidence to the contrary was all over their house. She also knew that Jyn was capable of surviving without her, and that Saw was ready to raise her. She also knew that there would be no time to cover her tracks to the hiding place. Finally–and this is key–Lyra knew one of them would crack under torture if she or Galen was a hostage. Thus, she made sure that the only option left to the Empire was to kill her.
And what better way to guarantee it than by brandishing a gun at the Director?
In conclusion: Lyra Erso died executing her own flawless plan.