I feel bad about what I just did, I stole money from a friend of mine.
Is that true? Why would you steal money from your friend?
I asked if I could borrow money from her and she said no. I was mad because I know she has the money and she's selfish.
It is okay not to be happy with a friend but you shouldn't steal from them. Even if they are a friend they can report you to the police and have you arrested.
I'm sure she'll never even notice the money is gone.
It's really not appropriate to steal money from anyone, especially a friend. She doesn't have to lend you money and if she doesn't want to, that's her right. You have to respect her decision.