Theft, $20,000 - 100,000

My question involves criminal law for the state of: Texas

A family member of mine was recently charged with theft of $25,000. When confronted by the police she asked for a plea bargain and they said they would give her one but would put nothing in writing as the DA was not present. They put her in the back of a police car (to record her is my assumption) and from what i understand she confessed in so many words. Now she didn't sign anything, and the officer told her that since she cooperated she could go but to be expecting a call within the next few weeks stating they had issued a warrant. After she receives the call she is to go down to the police station and turn herself in. My question is what are the odds the officer will honor the plea bargain? Also what kind of sentencing shes looking at if the officer was simply bluffing?

As she was told, the prosecutor makes plea bargains, not the police.

We have no way to anticipate her sentence as we don't know her record, the facts of the offense, whether she has made (or can make) restitution, or what plea bargain she might receive.

It is also important to point out that nothing the officer said in regards to her plea is in the least bit binding to the DA.