My 36mo old granddaughter may be having difficulty with speech development. She chatters, but often it is not possible to understand what she says. Though at times she is easily understood. She knows the letters of the alphabet, however does not speak the letters "l,f, s,r" . Her father had delayed speech and learning difficulties. Is it too early to have her evaluated? How would I go about helping this family determine what would be best for this child?