Tonsillitis does not cause sores in her mouth. This sounds like an illness called herpes stomatitis. Please have her seen by a doctor as she will not want to eat or drink and will become dehydrated.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.