In my house, my daughter is the one who watches all the channels, not me, so I guess some of her SS goes towards the cable. When I suggested we cut back on what channels we receive, she protested, so yes, the cable is "hers".
My daughter's SS is broken up this way:
Allowance (for gas, clothes, fun stuff, etc)
Car Payment - for the car she's driving
Car Insurance - for said car
Rest goes into a separate savings account which I use if need be to meet our monthly expenses. When she stops receiving her checks, whatever is left in the account will either go directly to her or to make a extra payment on her car.
I also, sometimes, get $$ from the mom & dad of the girl who is living with us. When I do, I put it in an envelope. If the girl needs something, I tell her to take some $ out of the envelope. If she gets reimbursed from one of her parents, she usually puts it back in the envelope. When she turns 18, I will give her whatever is left in the envelope. Sure, I could use the extra $$, but I don't consider it mine and as long as I can afford the basics for her (her sharing what we already buy), then I won't use the $.