Painful mouth ulcers in children are quite common and are usually caused by minor infections, stress, accidental biting, irritation from spicy or acidic foods, or sometimes nutritional deficiencies like low iron, vitamin B12, or folic acid. In some cases, viral infections can also trigger multiple ulcers at once, making eating and drinking uncomfortable. At home, giving soft, cool foods like curd, porridge, and banana, and avoiding spicy or citrus foods can reduce irritation. Keeping her well hydrated is important because dehydration can delay healing. Gentle mouth rinsing with plain water after meals can also help keep the area clean. Over-the-counter soothing gels or oral ulcer pastes are often used to reduce pain and help with eating, but it is better to choose them based on a doctor or pharmacist?s advice for her age. If pain is severe, a doctor may prescribe mild pain relief or vitamin supplements depending on the cause. If ulcers are frequent, very large, last more than a week, or are associated with fever or weakness, she should be examined to rule out underlying deficiencies or infections.