They have to commit criminal negligence to be charged with criminally negligent homicide:
PENAL CODE
TITLE 2. GENERAL PRINCIPLES OF CRIMINAL RESPONSIBILITY
CHAPTER 6. CULPABILITY GENERALLY
1.07 provides that the omission is an offense or otherwise provides that he has a duty to perform the act.
12.23.
Sec. 6.03. DEFINITIONS OF CULPABLE MENTAL STATES. (a) A person acts intentionally, or with intent, with respect to the nature of his conduct or to a result of his conduct when it is his conscious objective or desire to engage in the conduct or cause the result.
(b) A person acts knowingly, or with knowledge, with respect to the nature of his conduct or to circumstances surrounding his conduct when he is aware of the nature of his conduct or that the circumstances exist. A person acts knowingly, or with knowledge, with respect to a result of his conduct when he is aware that his conduct is reasonably certain to cause the result.
(c) A person acts recklessly, or is reckless, with respect to circumstances surrounding his conduct or the result of his conduct when he is aware of but consciously disregards a substantial and unjustifiable risk that the circumstances exist or the result will occur. The risk must be of such a nature and degree that its disregard constitutes a gross deviation from the standard of care that an ordinary person would exercise under all the circumstances as viewed from the actor's standpoint.
(d) A person acts with criminal negligence, or is criminally negligent, with respect to circumstances surrounding his conduct or the result of his conduct when he ought to be aware of a substantial and unjustifiable risk that the circumstances exist or the result will occur. The risk must be of such a nature and degree that the failure to perceive it constitutes a gross deviation from the standard of care that an ordinary person would exercise under all the circumstances as viewed from the actor's standpoint.
PENAL CODE CHAPTER 6. CULPABILITY GENERALLY
PENAL CODE
TITLE 5. OFFENSES AGAINST THE PERSON
CHAPTER 19. CRIMINAL HOMICIDE
Sec. 19.01. TYPES OF CRIMINAL HOMICIDE. (a) A person commits criminal homicide if he intentionally, knowingly, recklessly, or with criminal negligence causes the death of an individual.
(b) Criminal homicide is murder, capital murder, manslaughter, or criminally negligent homicide.
Sec. 19.05. CRIMINALLY NEGLIGENT HOMICIDE. (a) A person commits an offense if he causes the death of an individual by criminal negligence.
(b) An offense under this section is a state jail felony.
PENAL CODE CHAPTER 19. CRIMINAL HOMICIDE
I think her conduct fits.