The meaning of ‘balanced on the whale jawbone’

The meaning of ‘balanced on the whale jawbone’

The passage below is from Fathoms: The World in the Whale Hardcover by Rebecca Giggs.

The two girls are watching now, each with their own small bowl of whale soup, chewing with their mouths open. I remember the blue whale in the Perth museum, my first whale, running round and around it; a flash of my sister’s baby tooth, balanced on the whale jawbone. The strips of minke are a cocoa, brickish red, marinated in a sauce the shiny colour of an antique chair. To stall, I ask the scientist about the recipe, on which she will only say, it is traditional. To be clear: it was never my intention to eat whale in Japan. For one thing, my research so far had led me to wonder just how apt for human consumption whale meat is. But the accusation vegan seemed to carry more freight than a mere enquiry as to my tastes, and I’m still hopeful of asking a question or two of the whaler now hovering nearby. I make a snap decision.

In this passage I have questions on the bold-faced phrase.

Here the author abruptly recalls when as a child she and her sister visited a museum and doing some mischievous things.

Yes, they did some a-bit-far-gone foolish act (but I had mines to share). In the previous chapter she confessed she ‘sprinkled hair trimmed with craft scissors onto the whale’s jawbone’ and brought ‘a loosed tooth trailing red filament to deposit onto the blue whale’.

I get some understanding out of the phrase but still cannot visualize it.

First, the exact meaning of balance. Merriam-wester gives me the following meaning. Did I get it right?

https://www.merriam-webster.com/dictionary/balance

1a : to poise or arrange in or as if in balance

1. balancing a book on her head

Even if I am right about that, I have no clear picture, just some vague jumble.

Here’s my guess.

The two children frequently visited the whale museum. They wanted to put parts of their body on the whale’s. And based on the phrase in question I think once her sister put her baby tooth taken out on the whale jawbone.

(Am I right?)

Here’s my last question.

Why does she use ‘balance’ in the context?

Does it because she have to put it quickly so as not to be caught, so that it is on a precarious balance on the whale jawbone?

Please help me.

Thanks in advance.