kids and money

this i have been pondering for awhile, how much money a child should have access to and how? should they have money for school every day? I try to teach my kids value for money and good manners and all the things i was taught and more, and this morning my miss 12 tells me i HAD to give her $2 so she could pay back her friend kaitlyn, i asked her why and she told me that when they were at sport the yesterday at our local recreation centre and miss 12  had forgotten her drink so kaitlyn offered to buy her one, which is a nice thing to do for a friend right? well kaitlyn whips out her KEYCARD and buys whatever she wanted and my miss 12's water, after miss 12 has a swig, kaitlyn turns around and tell her she owes her $2!!! now I'm left wondering why the fuck a 12 year old even has a god damn keycard that she is telling everyone is her credit card to even be able to spend willy nilly like that, and also why you would OFFER to buy you 'bff' a drink if you are only going to ask for the money back ? In my day friends just bought each other stuff, if my mate bought me a drink I'd buy her one next time not expect the money back the next day! and my girl is just like me, she will buy her friend a drink or ice cream or something if she has the spare $$ and not expect anything in return and was a little shocked when her friend asked her to bring the money back to school today, and i might add i was a little peeved at the fact she just expected me to fork it over to her as well!!! I luckily had change in my purse to give her and at the same time told her to never make debts with her friends and expect me to pay them, yeah yeah im the mum and i have to pay, i know that but she needs to learn to take her damn drink bottle yeah? i have numerous ones in the cupboard she takes for the first week of school and then never takes them again!! Or have a drink out of the frigging tap like we used to when we were kids! Is this generation of keycard wielding kids greedy little buggers that dont know how to share? At any rate i know that i wont be getting my kids keycards until they have jobs to earn money to put on the damn things!!! vent over.... for now ;-p