She babbles constantly.
Will sometimes say 'ma' or 'baba' or 'mama' if I prompt her 'say mama,' but is just copying me, and mostly ignores me.
Will make a mooing noise when we read one particular book ('a cow says...'), and a kiss noise when we read another book.
She will shake her head no if she doesn't want to eat something.
Most of her baby friends are saying a handful of words by now. She also doesn't respond when I say things like 'come here' or 'don't throw.' Her hearing is fine, she responds to music and her name. Is this normal or late development?