Is OTHER wrong in the post ? POST : After I moved to a small town I was stalked by a person I didn't know, she became obsessed with me and even broke into my home at one point. (I wasn't home and she didn't take anything) Because of this I did not feel safe in this town so I left. I left rather quickly and on the night before I left I discovered a library book I had failed to return. My friend volunteered to return it for me. I agreed as it was late and I did not want to stop at the library on my way to the airport in the morning.
Fast forward four months: I had kept in contact with this friend, we talked once or twice a week. I had asked once, about a week after I left it she had returned the book and she said she would soon. I dropped it figuring she would take care of it. Then, last week, I got a bill from the library totalling $90 dollars. 
I was shocked and called her, I at first thought my friend had dropped it off and they failed to properly scan it back into the system. I was wrong. My friend had never returned it. I asked her if she could, if not I said, I could have my sibling who lived in the same town pick it up from her and drop it off. My friend said they could drop it off, it had just skipped her mind. Then she asked if I wanted help paying the bill, money was tight for this person so I said if they wanted to pay half it would be greatly appreciated. 
Keep in mind, this person volunteered to return the book in the first place, and asked if I wanted help paying.
I sent her a text a few minutes after our phone conversation to thank her for helping pay the fee.  It didn't go through, she blocked me. She also blocked me on sc, insta, and messenger. 
It's been a week and she still hasn't returned the book.
Am I the asshole here?? Did I somehow overstep myself? 