Is this normally for a 3 year old

[tyler's mum]

To start sucking her thumb when she has never done it before The past 3 weeks tyler has starting doin it she hides her head so its not like she is doin it for the attention. Nothing knew has change there are no kids around us who do it.

[delirium]

Have you had any changes in routine lately like moving house, a change of carer if she goes to day care etc? Has she been sick?

She seems to be doing it for comfort, so if she doesn't normally do it, you need to find out what she is seeking comfort for.

[tyler's mum]

No nothing has changes her behaviour has been a bit full on lately but beside that nothing else has changed