[Amelia waves a finger and magically shields the four of them and a large area of the fountain where the humming is coming from, from normal eyes. They won't be noticed at least. She's leaning over and frowning into the water.]

Alright girls, it's me. Fiona sent me and she says you haven't been behaving lately.

[The low pleasant humming suddenly lowers even more into a whisper almost caressing. Amelia responds as if she can understand it, rolling her eyes]

Fine, just one of you is enough. This is important though and don't even try your songs on these guys while I'm around.

[And from the water a head pops out-- or well, someone's head that looks like the water itself including white glassy eyes. A female figure that looks like it's made of the water emerges and uses a spout of water to reach their level.

It coos and hums curiously, looking particularly interested in Loki and Thor]