Soft quacks while on nest

[0iseau]

one of my girls, Sinclair, has decided that she wants to be a mom. She’s been giving me soft little quacks when I’m nearby but gives other hisses.
Does anyone know the meaning behind these soft quacks? I’m fairly certain they aren’t mean “get away from my nest” quacks.
If anyone with experience with broody ducks knows the answer please let me know!
The quacks

 

[Stipenvlerk]

Sounds to me like broody sounds..
However the link only provides a picture and no sound.