My rabbit died last night

Question
I got my bunnies on Easter of this year. I fed them rabbit pellets and bananas peels and avocados skins.  But one of my rabbits was not felling so well.  But the other two are wonderful no signs of being sick. She was ok all day and sometime last night she was not eating and just very tried so i pick her up and tried to get her pep up but she got worst.  I called a vet but they said they could see her but i did not have enough money.  She was pooping. What did I do wrong.  Was I feeding them the right food?  

Answer
Hi Angela,
First off,it's hard to determine the cause without knowing some facts..how old was she? Did she have a fall? Was she showing signs of illness? Did she happen to be pregnant?
I'm suprised they ate the advocado peels...I never heard of this before,being such a hard shell.
Anyways,I'm sure you did all you could to make her short life wonderful, sometimes rabbits can contract an illness and become very ill so suddenly.  
 Take care,Elizabeth