She is probably going to lay an egg! Some take longer than others in the nestbox. Leave her for a little while longer in the nestbox and see if she does.I have checked all around the garden for eggs. I found 2, but they were very old and I checked in the same place this morning but found none.
I left out the ducks at around 7:45 am this morning and Australis (the new duck) was in the nesting box so I decided to leave her alone.
My sister and I went out to say hi to the two of them later on (at around 10:00 am) and she was still in the nesting box. I went to check on her and she started hissing at me. Eventually she came out and we tried to soak her in warm water because we thought that she might be egg boud but she wouldn't stay still.
She is not under/overweight and she is acting normally but I wonder is she trying to hide the symptoms because I know that ducks do that type of thing.