You've got it right.
If she pulled her gun and shot with intent to kill, murder is the appropriate charge. 2nd degree, not first, because it's not premeditated, just in-the-moment. Orange Joe is talking about premeditation, not intent.
But yes; she should be convicted on 2nd degree murder for this. I'd actually argue they can overlook the criminal trespass possibility if it turns out that her victim had his door unlocked or something; just walking into the wrong apartment shouldn't result in charges. Dropping charges to manslaughter seems like preferential treatment for a police officer.
And before anyone accused me of being anti-cop, here's the Texas law code;
https://statutes.capitol.texas.gov/D.../htm/PE.19.htm
This wasn't "reckless". She had full intent to either kill or at least seriously injure the guy by shooting him. She was also arguably committing a felony (breaking and entering) at the time. I don't see how this ISN'T murder, under Texas law. It's not
capital murder, which is more severe (Texas apparently doesn't use first- and second-degree classifications). And she could potentially argue that it was a "sudden passion" thing for being fearful of someone she thought had broken into what she thought was her apartment. That would reduce the punishment to a second-degree felony.
But she still committed murder, under the law. Charge her appropriately. That she has a badge should only
ever mean that the punishment for her crimes will be more severe than otherwise,
never an argument for lighter treatment.