hello doctor's/mom's my 1 year ,4 months old doesn't respond to her name. she has good eye contact, points and tell what she needs, imitates us , follow small instructions like come here , give me ball, identifies cow, cat, dog. smiles at people. all but doesn't respond or turn her face towards us when called. but most of the time looks when her sisters name is called. what to do please help me . Is it really concerning. ?