I must have dozed in my chair
and was awakened abruptly
by the loud whistle of the kettle.
As I hurried to switch it off
in the distance I heard...

"We have gold and jewels galore
as we head back to the shore,
our treasure chest is overflowing
and it's homeward bound we're going".

- I really think you have done well with the little verses of song in these stories, I can imagine children learning them and beginning to chant along with them each time they read the story.
and...

As I headed into the garden
once more I wondered what
tales they would have to tell.

Terry-Tu was in charge of
counting the gold coins
"Un, deux, Trois" he began
until I reminded him to
speak English.
He was going to scowl at me I think
but smiled and continued
"Four, five, six"...

- you bring the cheekiness of Terry Tu back in here and it has a sort of motherly tone in it, that you are educating him and reminding him about his English. I also get the motherly tone because he respected you instead of answering back lol.

Hopper had an emerald
necklace and some
sapphires and diamonds.
He had sung for them
he told me and winked.

- I like the idea that you reminded us of Hopper's singing, and how he had used this talent of his to get the treasure.

Meanwhile, Jan de Bouff
was mooring the pirate
ship for the night.
He set anchor, rolled
in the sail and hopped
ashore to tally the loot.

- I think this puts it into place for the reader that he is indeed the leader of the rest and takes charge of the goings-on.

"A good job done, me hearties"
he said and they all sang...

"We're as rich as rich can be
we three pirates who are free,
look in our treasure chest and see
we're as rich as rich can be".

- I imagine the cheer here that the pirates do in films when they have got their treasure box and celebrate. Nice little chant to add in again, with good flow and rhythm to it.

Later that night, as I tucked
my little two year old pirate
into bed he asked "Granny...
who will we be tomorrow?"
and...
As I put Terry-Tu and Hopper
the puppets back in the toy box
I spied Dotty, the giraffe
Eleanor the elephant and
Zoe the zebra and smiling
I thought...tomorrow
we will go on SAFARI!

- comma after giraffe, since you are making a list. you could also add in : after I spied, to show you are then going on to make a list.

I love the little ending and how it has been a puppet show all along, also how the reader can get a feel for the close relationship between the little boy and his gran, that is lovely. You can imagine his head filled with these adventures and to be in his dreams that night.

The Safari Park sounds like a great adventure! I can't wait.