This is probably only a habit but it is rather unuaual and I have not come across a situation like this in a young toddler before. It would be best to ask your paediatrician to see her just to be sure that all is well.
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.