Granny, its sooo lovely to hear of grandparents being concerned about their grandchildren - please dont ever feel over anxious! As HJT40 so rightly put it - its your job to be concerned about your family, why would you be?
My youngest nephew suffers from slow speech development and wasnt even giving eye contact - he's barely three years old and has already had two courses of speech therapy and has just statred at nursery. Half of his problem was too much tv and not enough communication from real adults.
Sadly, i dont get to see him very often, but whenever i am with him i sing to him. He loves it soo much that he started singing back - just small sections, one or two words, but it was a start. i then added his name into the songs and this kept him occupied for 7 - 10 mins! He nows stops and grabs my hands in a wavy movement and begins to sing his favourite song 'Jig Jog'.
I have now been told that he has been sitting for longer since he has been at nursery - so there is still hope. I'm now in the process of making him his own song book.
I do believe that he will develop at his own pace as do all children, but a little bit of support from specialist wont hurt.
Good luck and keep up the worrying ( Meant in the nicest possibly way you understand!)
Flower xx