Not saying it can't be done, but... 2 of your 4 people are tiny children!
I can usually get 2 meals for 2 adults out of 1 chicken, so I'd welcome your stretching advice! 
One with a VERY big appetite who is getting even taller and whose fav food is chicken.
K, though, I rise to the challenge!
My first way of stretching is to roast the bird first. Eat off it.
Then strip the hell out of it the next day.
You'll be surprised how much you get!
Then I usually do one of several things with it:
a) coronation chicken salad
b) chicken rice - known as 'chicken risotto' on the Hugh programme
c) white bean and chicken chilli - i'd be happy to post the recipe if you'd like, it's a slow cooker one!
d) chicken stock - i use this as a base for a soup.
e) chicken meat balls - take the stripped chicken and put it in the food processor. Shred it to mince, basically. Mix with breadcrumb, egg and whatever seasonings you like. Make into balls an bake in the oven at about 160C till golden. Serve on a roll with tomato sauce, pasta, or rice.