This is actually what OPs said:
I can't afford to keep forking out, she gets bought her own food but she stuffs it all at once and then moans that there's nothing for her to eat!!
So, what is bought for her, lasts this girl a couple of days, then "her" food is gone. And tells an adult she's got nothing to eat. But she doesn't get any more of "her" food. OP says she can't keep forking out, so it suggests this might be a cost thing. She's hungry and nothing is "hers" from day two.
She chooses what she wants from the shop and she get it bought for her.
Well this depends, is she saying "crumpets" for breakfast, and being bought a single pack of 6. And as a hungry teen eats three in a sitting. So that's her breakfast gone in 2 days. And that's that. When the reality is she needed two packs from the start. It's 60p we're talking here. And to be allowed some toast if needs be to topped up. But she gets enough to actually last her two days, and that's deemed plenty. It's not if it's routinely lasting her two days.
She won't go and replace them, she'll just point blank refuse and there's no way for me to make her.
A child isn't responsible for replacing household food when there isn't enough for them in the first place.
She has a part time job but she's wasted all her money on McDonald's, same reason, she's eaten all her own food
Why is her having to buy extra meals because there's not enough being allocated as "her" food, her wasting her money? This is not what her wages are for. One offs sure. But always? This is a child using the small wage they get, to supplement their food intake because what she gets doesn't cover her needs.
Yet again, OP points out this is because all "her" food is gone. How is this not getting really obvious by now?
To make one thing clear. She has plenty of food.
Really? Because up until now, it's really looking like she doesn't.
I'd never let her go hungry, when she's not at work
But all her food is gone, she can't keep going to McDonalds, and OP isn't "forking out"
either she's just too lazy to make herself anything and I'm at work during the day too so I'm not around to.
Ok. So does she see it as there's "her food" and "everyone else's food.". So once her food is gone, anything falls under "not hers.".
The bread she would use for a sandwich. That's not hers. That's for her dad's breakfast. Not hers. And she's got to turn that bread that isn't hers into a sandwich.
Or there's the cereal bars for tomorrow's packed lunches. Not hers. But they don't need making into anything.
Best go for the easy option that's not hers instead of the more effort version that's not hers.
If there were a pack of no effort sausage rolls (£1) that were hers, guess what she'd be eating!