But, the fact that she intended to kill means she didn't commit manslaughter. Guyger was not charged with manslaughter because she didn't "recklessly" cause the man's death. She herself testified that she shot him with the intention to kill.
That's why she was charged with murder (and not manslaughter). If you intended to kill, you didn't commit manslaughter.
Some "intents to kill" are legal, and some are not.
Sure, sometimes people shoot to kill in self-defense, for example. In this case, her attorneys brought up Castle Doctrine as a defense. But, the reality is that Mr. Jean was sitting in his own apartment, and she went into his apartment and killed him. That wasn't self-defense.
Apparently, Texas has only capital murder (where the perp faces the death penalty) and murder (where the perp faces 5-99 years). She was rightfully charged with murder. She was rightfully found guilty.
Apparently, in Texas, after a murder conviction, the jury then takes other factors into consideration when they decide on sentencing. A few of you here were complaining about the murder conviction before she was even sentenced. Now, as you can see, her sentence is pretty much a slap on the wrist.
I think the interests of justice have been served, even if they went down the wrong path to achieve it.
Believe as you wish, and have a nice day.