{I'm not sure... what's difficult about staying underwater for a long time?}

"You run out of air." 

"I'm not sure I need to breathe. It seems like a bad idea to test." 

{there are some items that are magic and I don't know what all of them do... there might be something that would work but I don't know what it is.}

{could ask cloud spirit,} the forest spirit contributes.

"Yeah, okay, we probably don't need deep seaglass immediately." She picks up her pickaxes, trundles out of sight, and begins digging. 

There is dirt!

Beneath the dirt, there is stone!

And mixed in with the stone—

The first ore deposit she finds is shiny, dark, and bluish-grey. There are a dozen blocks of it all clustered together in a lump. She's about ten block-heights down at this point.

Well that was easy. 

She brings the ore back to her brother and goes back to dig some more. 

The next one, thirteen more layers down, is sort of a muddy desaturated orangey-yellow colour. There's only eight blocks of it.

...Huh. She mines it out and examines it. 

It doesn't tell her what kind it is, because it has no by-hand crafting recipes and so cannot name itself in their ingredients lists.

Oh well. She crawls out of her hole and brings it back to Wilbur--

Who now has an advanced crafting table!

"Any buckets?" she asks, bouncing. 

Headshake. "That metal was lead." 

"Ooh, yeah. Well, I don't think this one is," she says, hands it off, and goes back to her digging. 

She finds another lead deposit, and then nothing for a while, and then something that looks suspiciously like copper—almost two dozen blocks of it.

Huh, neat. Maybe it is copper. 

She brings the ore back up and to Wilbur, who to her delight has in the interim produced eight tin buckets. 

"How big do you want your pond?" she asks the water spirit. 

{oh goodness, I don't know! maybe four or five blocks across? is that a good size?}

"I could do bigger easily. Maybe one that size indoors, so you can come in at night when the monsters arrive, and a bigger one outside?" 

{okay!} The water spirit bounces slightly with excitement.

The spirits are so cute. 

She quickly digs out a shallowish hole in the ground, no deeper than Wilbur could stand in and have his head above the edge, then goes into the house-in-progress to set up an indoor wooden pool. 

Then she heads off with the tin buckets (and four copper ones Wilbur made in the meanwhile) towards the river, keeping an eye out for tasty slime. 

There's a green slime! Does that qualify as tasty?

Tasty enough to eat, not tasty enough to enbucket for Wilbur. Nom. 

When she reaches the river, there's one of the rainbow ones hopping determinedly against the current.

YES!

She grabs it triumphantly, wrapping one tentacle around it as thoroughly as possible and surrounding it with buckets before popping it. 

It wiggles frantically, but is unable to escape before she crushes it.