According to Mississippi anti-cruelty law, it's a misdemeanor to intentionally deprive a domesticated cat of food, water and/or shelter. If you adopt a pet, it's your responsibility to care for it. She would have had to sign paperwork during the adoption explaining all of that. And most rescue leagues ask that you contact them if the placement doesn't work out for any reason.
MS anti-cruelty law (http://www.animallaw.info/statutes/topicstatutes/sttoac.htm):
This section constitutes Mississippi's anti-cruelty and animal fighting provisions, which were recently amended in 2011. The pertinent anti-cruelty law, § 97-41-1, states that any person who intentionally or with criminal negligence overrides, overdrives, overloads, tortures, torments, unjustifiably injures, deprives of necessary sustenance, food, or drink, cruelly beats, or needlessly mutilates any living creature, is guilty of a misdemeanor. The cat and dog cruelty provision, § 97-41-16, was significantly amended in 2011. This section, known as the "Mississippi Dog and Cat Pet Protection Law of 2011," makes it a misdemeanor to intentionally or with criminal negligence wound, deprive of adequate food, water, or shelter, or carry or confine in a cruel manner, any domesticated cat or dog. Aggravated cruelty occurs when a person with malice intentionally tortures, mutilates, maims, burns, starves or disfigures any domesticated dog or cat.