"Well, probably, nothing will happen, but possibly, I would one day meet a random mortal who puts slightly more nutritious rocks in the water and they'd be able to give me orders."

"I mean.  I can give you water by hand forever if you want."  No!!  Sound more normal than that!  "Or I can start buying distilled.  I don't know how expensive that is but it's probably fine."

"Distilled water would be safe."

"I will buy you distilled water at least until we've done enough research to be sure tap water is safe."

"Thank you. ...how does buying things work?"

"Either you go to a store, which stores things for people to buy, and give the people there an amount of money that will let you take the thing you want - is there money in Fairyland?"

"No."

"Okay, well basically it's a thing that you can give to people in exchange for things, which works because those people can also give it to other people in exchange for things they want."

"...is it good for anything else?"

"Not really."

"Why wouldn't you use something that is?"

"Uh, because then people would use it up instead of having money?  You can look at my Gov/Ec textbook if you want, or the internet.  Money is, kind of one of the big things in human society, for good or for ill, and so everything about it is pretty important.  But not in a way where I, a regular person, understand all the reasons why it is the way it is."

"The textbook might be neat if it doesn't assume too much background knowledge."

"...It would probably do that."  He stabilizes Hawk with one hand and shifts his chair to face the desk a bit more.  Laptop open, Simple Wikipedia, money.  He passes it to Promise.  "- Oh, you can scroll by - you can make it show text that's lower, like with turning page, by... probably the mouse is the easiest way."  He turns that on.  "By moving this wheel."

"Why is it written like... that."

"There's one that's in regular English but I thought it might assume too much background knowledge so I went with the simple one."

"It's not the words that are likely to trip me up. Or, not the kinds of words this is avoiding - I don't know what a cow is."

"A cow is an animal that both produces and is a thing that humans can eat.  Here, let me -"  He takes the laptop back and replaces the 'simple' in the address bar with 'en'.  "...I'll be surprised if this is more illuminating than the other one but of course you can look at it."  He passes it back to the bed.

"Why is some of it blue?" is her next question.

"Each of the blue bits connects to another page like this on that subject."  He squints at the screen.  "Or, well, some of them are citations or other things that'll hop you to stuff within this same page.  You can use the mouse to interact with them, by... hm, I'm going to put the cat out so I have more freedom of movement."  He does that.

She waits patiently.

And then he can sit on the bed next to her and drag the MDF board to where it's most useful as a mousepad and show her how to click on things.

In that case she will soon have a tabsplosion on her hands.

And not long after that there are noises associated with his parents coming home.

While they're still in the garage: "- Can you write?"

"Of course I can."