you need to be really strong about this if you want to turn your family's eating around.
The first is don't buy any junk food - one of the things that happens to people that eat rubbish is that lose all tastes for natural food, so trying to offer wholesome food whilst junk is around or in a 'treat' box, is never going to happen.
Get the family together & explain that you're all going to be healthy & fit & it's going to be great because you'll have lots of energy & look fantastic. Don't make it more complicated, just be matter of fact.
Write a menu for the week, do this when you've got a quiet time over the weekend & then tell the family from Monday it's going to start. I wouldn't bother weighing anyone, because as weight comes off, you'll see it.
Stick to 3 healthy meals & 2 snacks a day - cereal (will they eat porridge ? , semi skimmed milk, apple or pear slices
Snack, have a banana, a qood quality snack bar (goodies, eat naturals, or make small savory muffins)
Sandwiches (wholemeal bread), chicken/tuna/egg/cheese with cucumber slices, cherry tomatoes. Another piece of fruit or a yogurt ( I prefer the organic ones because they have, as well as organic milk, less variations of sugar)
Have a smoothie or more fruit after school.
For, ditch the meat, eat red/green/brown lentils in bolognese sauce, make your own tomato sauce (tin toms, tsp sugar, dried basil + onion). Use wholemeal pasta always. Brown basmati rice. Use natural yogurt instead of white sauce in lasagne.
You can still have puddings, cook fruit crumbles & have a small amount of cream (unless you buy a good quality ice cream)
Get the kids cooking oaty biscuits, little fairy cakes (made with butter)
The key thing is not to say we're on a diet, but to re-educate their tastes & they will (eventually) enjoy it.
Failing that, she can come & spend the week with me !!