I read through the localized manga, and I noticed a major difference between it and the fan translation on Page 12 of Chapter 13. For context, Shizuku's on the train and worrying about how her apology to Ruri will go.
In the fan translation, Shizuku thinks, "Back then, I basically just had my mom make a formal apology. I can't repeat that."
https://dynasty-scans.com/chapters/kimi_to_tsuzuru_utakata_ch13#11
In the localization, however, Shizuku thinks, "Back then, my parents had me apologize and promise never to do it again."
I'm curious as to which is correct, but I'm leaning toward the fan translation- you can see Mrs. Hoshikawa seems to be bowing but Shizuku appears to be standing up straight, implying that Shizuku couldn't apologize (most likely due to nerves after seeing the mother of the girl she bullied), or chose not to. It also fits with how Shizuku is determined to actually apologize this time.