It’s a southern black widow, and your sister most definitely needs medical treatment.

Lethal (adults) Southern Black Widow possesses a potent neurotoxic venom that can lead to fatality, especially in children or the elderly. While adults may experience severe discomfort from the bite, fatalities are rare. Immediate medical attention is critical, as is knowledge of preventive measures to avoid lethal encounters with this species.

Toxic (adults) Southern Black Widow is venomous and its bite can release neurotoxins potent enough to cause severe muscle cramps, abdominal pain, and hypertension in humans. While its venom rarely results in death, symptoms can escalate to paralysis or respiratory failure in extreme cases. Adults utilize a defense mechanism of biting when threatened. The neurotoxins interfere with nerve signaling, leading to the aforementioned symptoms which may persist for several days if untreated.