I could relate to it in a funny way. I was in a situation like that from the other side in 1990. I was in a toxic friendship with a guy I wanted to give the flick, and I had moved to another country. He came to visit me and found that the dynamic between us was just not the same. He sent me a nasty letter two weeks after he returned to the US. I used this as an opportunity to give him both barrels in my letter back to end the friendship. Found out later that he'd been scared to open my letter because he knew what it would contain. Then he cried for the rest of the day after reading it. So, yeah, it always seemed obvious to me what Hollyhock's letter was going to contain, one way or another.
I honestly knew it was coming. Hollyhock seems like one of those people who won't tell you in person if she has a problem because she doesn't wanna hurt them so she'll write it down so she doesn't have to see their reaction