£100-200 at a friends house? fair or not?

I'm 13 :) and sorry for the long text! So, I was talking to my friend and we were meant to have a party in summer but I can't do it with her cos I will be on holiday.. so I said to her that I was mad and that I which I could still do it and that my mum said that if it was that important I should stay with her 2 weeks until she comes back (even tough she'll never ever let me lol) and so I said that to my friend and she calls me and tells me that I should bring £100 or £200 when I go to her house for food so I was like '???' and my mum would never tell her to pay.. btw she has 1 sibling and I wanted to know if that was fair that i had to bring that much at her house when I don't even eat that much and the worse part is that when she comes to my house she takes all my food and never ever say thanks and stuff, she just help herself in my fridge and at her house we're not allowed to do that! That's like soo not fair... She's not allowed to eat as much as she does at my house at her house! And I will never do that at her house (help myself whenever I'm hungry- I'm always hungry) What do you think?? I think she asked me that amount because she wants a new phone like ne (iphone) and it's too expensive so she can't get it! So she'd like more money!