Aka: Why Dutch, Belgian and Scottish mermaids would not get along
I feel like people often forget that it’s sirens, not mermaids, who sing to make sailors shipwreck on the cliffs. Furthermore, while sirens are pretty much confined to Greek mythology, mermaids show up in many different folklore traditions and they actually differ quite a bit across cultures. So please, allow me to introduce you to:
The Belgian mermaid. Their song is beautiful, but it is safer to listen to them from a distance. When they sing under water it’s usually safe, but when they come to the surface and you hear their song above the waves, you can be sure there’s a storm on the way. The mermaid’s song warns for rough weather and wise sailors and fishermen heed it.
The Dutch mermaid. Honestly just wants to be left alone. When they sing, it’s usually a prophecy and hardly ever good news. Whenever someone finds and catches a mermaid, either she or her family will start singing verses, fortelling bad omens, promising floods, poverty and ruin to the captors, until she is freed. The humans rarely show mercy and the prophecies always come true.
The Scottish mermaid. Often does have an alluring song, but lures people out into open water, after which she causes a storm that sinks the boat and drowns everyone on board. Most of the time this seems to be a recreational activity and occasionally it’s for some sort of revenge. They can also cause literal tidal waves to crash into the shore.
Which brings me and @petalproufaerie to the conclusion that this collection of cousins would not get along at all. The Scottish mermaid would be luring people into mermaid territory, greatly upsetting the Dutch one, who’d probably get herself kidnapped. Both of them would them probably proceed to either cause or predict a storms, so the poor Belgian one has to swim up to the surface and sing to warn everybody.
...then again, Belgian mermaids are not at all fond of being kidnapped either and unlike the Scottish stories it is not at all clear whether Dutch mermaids can actually cause storms and floods, or if they only predict them. So maybe they predict them first and then run crying to their Scottish cousins asking to summon a tidal wave or two, probably as an apology for luring the humans out here in the first place.
Still, the family gatherings must be tense