This looks to be a criminal defense case and not a "personal injury" case. A district attorney can always choose to pursue charges against an accused regardless of whether the victim is willing to testify.
Typically, in the State of Texas the decision to charge or not charge is exclusively up to the prosecutor. The complaining witness does not have the actual power to either compel prosecution or dismissal. However, it is the rare prosecuting attorney who will not at least listen to the "victim."
On a more global view, injury to an elderly or disable person is a serious felony grade offense, the actual level depends on other factors. A felony of this type can be reduced to a lesser charge, but whether or not it WILL be is up to the prosecutor. The specific facts of the case and the skill of the lawyers involved will enter into any decision to reduce or dismiss. Be aware this isn't television, post indictment dismissals do happen, but don't bet on getting one.
A good general rule of thumb in any situation where a person is concerned about a criminal accusation is immediately retain a qualified lawyer and take no action nor make any statements until assisted by that lawyer.