Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by the two week infant sticking her tongue in and out quite a bit.
Newborns do not consciously stick out their tongues, but newborns have an instinctive suckling response, which involves the muscles of the lips and tongue. That response can get triggered even when the infant is not feeding, leading to lip smacking and tongue movement. So this is quite physiological or normal and might be a sign of hunger in some babies.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.