I feel for her, but how many times have we heard this story before?
Not her specifically.
Don’t try to stop thieves.
Didn’t an older man just die from getting punched at work recently?
The proper thing for the company to do would be tell her thanks for her efforts but not to do that in the future as it could risk her life. THEN if she violated policy again they could fire her. To fire someone after thirteen years of loyalty to the company over such an issue shows the loyalty goes only one way.
You can be sure the policy is set by underwriters who do not view the merchandise the insure worth not only the employee’s life but a lawsuit by parties involved or (if the worst happens) surviving relatives.
Bottom line, The goal at the end of the shift is, Go home to your family. Let the security of police go after the thieves.
A sympathetic judge and jury, with a sizable award or settlement to the fired employee would tend to mitigate the punitive behavior against the employee.