To treat a blood clot in the leg (Deep Vein Thrombosis), she will need prescription medications called anticoagulants (blood thinners) to prevent the clot from growing or travelling to her lungs. Commonly prescribed options include oral medications like Apixaban (Eliquis) or Rivaroxaban (Xarelto), or injectable heparin. She must consult a doctor immediately for a proper evaluation and prescription, as the correct choice and dosage depend on her medical history. If she experiences shortness of breath, chest pain, or rapid heart rate, seek emergency medical care immediately, as these are signs of a life-threatening pulmonary embolism.