Well I'm not going to be a dick and say the OP is shit at her business because her profit margin is low.
It's neither here nor there (and certainly not up for comment or discussion) why she's not able to afford to feed her dd when she's at home.
The fact is she has told us that her money is tight.
Let's move on from the smug "well my business makes money, and I plan for contingencies, therefore the OP and her DH are faffing about with their hobbies" because it's not helpful, and only makes the op feel bad, which I'm sure is no one's intention, right?
I did the hot bed and sofa surf thing while working and paying for myself through uni, and while it wasn't great, I feel proud of my achievements. My parents couldn't help me at all, and I worked hard and got scholarships, and worked every summer, all summer.
It's not ideal to work all the holidays, and not have any time to rest and recuperate, but starving is pretty shit too.
Op if you're coming back, and not a dailyfail journo sit your dd down and let her know that you can't afford to keep her, but that every week you will buy her a half a dozen eggs, a block of cheese, a litre milk, a big bag of pasta and three tins of tomatoes, a bag of rice and two tins of kidney and butter beans, a bag of onions, a clove of garlic, two courgettes and two peppers, and and she can make a rice and bean with veg stew every week, or pasta with tomato sauce, and she can eat that.
Ask her for a 25£ contribution for food and a 5£ contribution for laundry supplies / hot water.
It will give her a real idea about the cost of her staying at home is for you, a babysitting job or dog walking would cover her food and laundry bills.
If she wants anything extra, she can get it herself and might spur her on to get a better job
Don't feel ashamed of your lack of money, or guilty that you can't afford to feed her: life's just hard sometimes.
I hope things turn the corner for you all.