Since the fever has persisted for four days despite taking an antibiotic and a paracetamol-based cold medication, it is important to consult a healthcare professional for a proper evaluation. The fever may be due to a viral infection, such as dengue or influenza, which antibiotics cannot treat, or it may require a different targeted therapy. Please avoid self-medicating further. A doctor will likely recommend blood tests to identify the exact cause. For now, ensure she gets plenty of rest, stays well-hydrated with water and electrolytes, and uses plain paracetamol for fever control under medical guidance.