No she is not the right person for a trained guard dog. Neither are homes with small children without very specific precautions. LARGE black dogs, big labs, black danes, even dark standard poodles (excellent indoor small children dogs) all offer deterent and watch potential without adding the worry and legal and training problems associated with a trained protection dog.
Many many many insurance companies will DROP a homeowner for having even ONE german shepherd that isn't trained, a trained one will usually get you dropped from the REST of them. One bite even justified and you can and often do lose your coverage.
Or if you're us, having five shepherds at one time can make it a tad challenging to find an insurance company.
Shepherds retired or not are not for people without the time to train. One that has been trained to bite humans, even MORE SO.
Under good leadership and good training, a good shepherd is excellent with their own children. Often not so much the neighborhood kids. Sometimes yes, often no. The less training, the less work, the less the exercise the greater the hazards.
Labs, Danes, Standard Poodles, all tend to make other people go somewhere else without posing the same legal and leadership issues.
They're much better starter dogs.