That is burglary. We were discussing trespassing.
How does 30.02 not fit?
Sec. 30.02. BURGLARY. (a) A person commits an offense if, without the effective consent of the owner, the person:
(1) enters a habitation, or a building (or any portion of a building) not then open to the public, with intent to commit a felony, theft, or an assault; or
(2) remains concealed, with intent to commit a felony, theft, or an assault, in a building or habitation; or
(3) enters a building or habitation and commits or attempts to commit a felony, theft, or an assault.
Did she have the express consent of the owner to enter his habitation? She did not. That's burglary under 30.02.
Once inside, did she commit a felony? Yes she did; criminal homicide. (30.02.a.3)
By her own admission during testimony, she intended to kill Jean.
Sec. 19.02. MURDER. (a) In this section:
(1) "Adequate cause" means cause that would commonly produce a degree of anger, rage, resentment, or terror in a person of ordinary temper, sufficient to render the mind incapable of cool reflection.
(2) "Sudden passion" means passion directly caused by and arising out of provocation by the individual killed or another acting with the person killed which passion arises at the time of the offense and is not solely the result of former provocation.
(b) A person commits an offense if he:
(1) intentionally or knowingly causes the death of an individual;
(2) intends to cause serious bodily injury and commits an act clearly dangerous to human life that causes the death of an individual; or
(3) commits or attempts to commit a felony, other than manslaughter, and in the course of and in furtherance of the commission or attempt, or in immediate flight from the commission or attempt, he commits or attempts to commit an act clearly dangerous to human life that causes the death of an individual.
She committed the felony of burglary and in the course of that felony, committed an act clearly dangerous to human life which resulted in the death of an individual.
That makes her guilty of murder. (30.02.a.3 & 19.02.b.3)