Maybe it’s because it’s been so long since the previous chapter, but this didn’t feel believable to me at all.
Who is this mermaid girl? Why is she suddenly important? Why is she here the exact day her curse victim is here too? Why is she grieving her actions just now and never once before? About the only reaction I bought into was the mother’s; she doesn’t know this girl, so she has no reason to feel any sympathy, and neither do I.
Hopefully the next chapter contextualizes this better.