Who suggested she believed it was a robot? I don’t think anyone thinks she’s delusional....she’s just mentally incompetent. That’s why putting a bottle of water, which a puppy wouldn’t be able to open, doesn’t make any sense to people who ARE mentally competent. And neither does covering the holes you made with tape.
That is what she told the employees, deliberately lying to them. She is clearly sufficiently competent to realize she was engaging in illegal and immoral behavior since she is sufficiently mentally competent to lie to the postal employees about what she was mailing.