My daughter is 11 months old now and is still not waving a bye even after repeatedly training her.. When we say bye she just turns away her head.. However she is talking few words, dances well for music, claps well and gives a hi fi and responds for her name.. Even identifies crow  car, dog and tells their name in her language.. But does not point to them...I see other babies of her age wave a bye well... When I say bye to her she turns to the door and pushes herself that way with a gesture to go out... Is it a cause for concern.. And till when should I wait to see if she does these actions