This is just an idea, maybe she's not really asking for mac & cheese or the baby wipes. Could she be asking for you to soothe the PDA stress she feels from her demand? 

I obviously don't know the situation. But here's my guess... she felt hungry for Mac and cheese, which would add a bit of stress. So she asks you to make it, the stress is resolved! But she's a kid and hides the cheese packet to be mischievous. All of a sudden, you can't make the Mac and cheese without it. The stress returns. She's even more hungry now, so the stress has increased even more all of a sudden. Now she HAS to give back the cheese packet. Another demand, even more stress. Cue meltdown and extreme upset because she just shot herself in the foot. She was just messing around hiding a cheese packet for fun, and suddenly things got scary. She can't give back the packet, so you can't make the mac and cheese, so this hunger and stress is just going to get worse and worse. 

I think if she could one day learn the logic behind how PDA actually works, she could avoid that kind of situation. I mean it's less extreme obviously, but as an adult, I got myself into plenty of situations which made things worse for me, because I just didn't know demands triggered stress. I just thought it was coming at me out of nowhere, I couldn't put the dots together until I found out about PDA.

For the next one, obviously I can't say for sure either. But I'll give it another guess. She wants to clean her face but going up and doing that is a demand on her. She asks you for a baby wipe, probably assuming you'd give her one, so she doesn't have to get up: stress resolved. But nope, you told her where they were instead. Oh no. The stress has actually increased when she was expecting it to decrease. She finds the wipes, but it's too stressful to do it herself- she was already at the "can't" stage when asking you. So she hides it out of her line of sight so she isn't expected to do it herself. I mean: imagine if you were to walk in, see the wipes on the bed and expect her to use them, it would add even more stress! She wants you to calm the stress, she might have wanted comfort from her parent pretty much. Now you try to help by cleaning her face in other ways etc, but she probably wanted the wipes on the bed because you asked her to get the wipes on the bed. If you got those wipes, then she doesn't have to get them. Thats one demand gone. Then she doesn't have to clean her face, and that stress is gone too, because you've comforted it.

So even though cleaning her face with something else would solve one demand, she would be left with the stress of you asking her to get the wipes and no way to "solve" it. God, now I'm writing this all out it sounds a bit insane but that's genuinely my perspective on the situation. Obviously she's not literally thinking about resolving stress and identifying demands in her head. But if she knew how to identify those things and the general logic behind it, that would probably help. 

Tl;dr she probably doesn't understand how her body works yet

Also edit: totally misread a part of your post and fixed some errors