Does it have to be a chirp or can she click her tongue or something instead? Is that more or less expensive?

It could be any kind of noise she wants but something high pitched and clear, like a chirp, works best? The red cost of this is really minor, like 5%. The blue cost depends on how sensitive she wants it to be.

She doesn't need it that sensitive, enough to aim at the center mass of a large animal and not walk into walls in the dark will about do her. She doesn't want to spend 5% of a gem on being able to squeak unless it saves her a lot on the blue end.

Eh, save on blue? Not really. What's left of this blue gem probably will suffice for that unless it's a very very quiet large animal.

"Was it very quiet on its feet, do you know?"

"...Dunno. Didn't go close. It roared."

Then probably it does not rely too much on stealth. Echolocation-except-not-with-chirping, go.

Shiiiing. Behold, a new sensory modality! The kid, and the donkey, are breathing. She's in a cave and can just Know its rough shape. The exit is that way, it's windy out.

Cool. "Pretty sure I'll notice if it comes in," she tells him.

"Good... Mrrrhmmmm... I'm a little scared to get more magic because what if I made bad choices, but I think it's good. The selectively permeable sphere. I thought about how to move it around and how tough it is and things like that..."

"And if you drop it you probably don't want it to sink through whatever it falls on."

"Thought of that, I control where it is with my mind. And how big it is."

"If you can fit it neatly, sounds good."

...He takes a deep breath and activates it. A blue gem dulls, and the black one does slightly, too.

And then there's a subtle shimmer in the air, a ball discernable as a transparent bubble.

"...I don't know how fast it will be. Depends on how dry the air is, I guess?"

He squints closely at the bubble, looking for... Condensation or something.

"It doesn't feel particularly humid or dry to me right now in here."

He waves it around some.

"-Ah, look, fog! It's working!!"

"Not really enough to drink, but soon!"

"I don't remember how much fog weighs. The sky is really big, so even if it can rain a LOT maybe not that much?"

"Are you running out of translation?"

"...No? I'm not out. Kinda close though."

"I ask because that didn't make sense."

"Fog has to weigh something, right? Because it's water. Just floating water. But it's not important I should save the last of the magic. Umm... Maybe just some being tougher or faster would be good. I don't know."

"Fog has mass. I'm going to go for an electricity power, because if I do it right I'll also be able to keep this working," she indicates her everything. "And it can do several different useful things, though not nearly as many here as it can on my planet."

"Oh, like telegraphs? Those are electric. And I think... Magnets or something..."

"Yes, like those."

Red gem (though she'll be touching a few others if they want to chime in), here's what she knows about how electricity works and the specs for her pocket everything, what can you do to let her keep the everything operational and maybe zap stuff less gently also?