I love it! Four points!
AWESOME. I think I may even have some of those left from before the dog chewed up my last anti-teeth-grinding device and I was keeping it clean. With blue glitter — perfect. Let’s see, fourplussupermaxhonorablemention for you!
Why, thank you.
snerk! Missed this earlier. With the proper font, a nice rich parchment background from the color laser printer, and a faux-Latin suffix or two, it’d be golden 
^ I was going to suggest that, too.
It may be too complicated, but some basic household ingredients can be used to extract DNA. Use a glass rod to stir the final separation and the DNA sticks to the rod like some sort of disgusting snot that kids seem to think is funny.
You’ll need:
Dish soap
Table salt
Water
Rubbing alcohol - ice cold (Higher the concentration, the better - this ingredient requires adult supervision)
And something you want to extract the DNA from. Strawberries work really well.
You’ll want hardware like:
a ziploc bag
a coffee filter
a glass rod, or chopstick
a small juice glass or test tube
Mash up the fruit inside a ziploc bag. Carefully add dish soap and salt. Let sit a few minutes.
Strain mashed fruit through a coffee filter into a small juice glass or test tube. Gently squeeze all the liquid through the coffee filter.
Carefully add ice cold rubbing alcohol to the liquid in the glass. You are trying to make two layers of liquid, not a single mixture. You should start to see some goop separating out of solution at the boundary between the two liquids. That goop is DNA.
Stir gently with glass rod or chopstick. This should wrap the DNA around the rod. It looks a bit like snot, frankly.
Some mineral oil. It won’t mix with water-based potions, which might be interesting. Available at the drugstore. Cooking oil would work too, but can acquire off flavors or whatever, and isn’t perfectly clear like mineral oil.
Gelatin sheets or powdered unflavored gelatin? Not an instantaneous thing, though. Ditto tapioca pearls.
White glue (like Elmer’s) mixed into water thickens and sort of “stabilizes” it, making glitter or dabs of color stay more in one place. My daughter likes to do this in a paper bowl then use her markers to “tie-dye” the surface.
Nail polish does wild things when you drip it onto the surface of water. It spreads out, creating a super thin coating, which you can then dip pieces of paper into. IIRC plain clear polish will give the paper an opalescent cast.
Speaking of Elmer’s glue, you can mix it with borax to make slime. Important note: There are two different formulas used in Elmer’s glue. You need the one that is not labeled “washable”.
And I don’t know what you’d call it, and it dries out quickly, but you also want ooblek. It’s just cornstarch and water (coloring optional): Add gradually until it’s the right consistency, and you get this weird stuff that’s liquid when it’s treated gently, but solidifies when you do anything sudden with it.
Careful! Iggy used to be “Ziggy” until this experiment blew the “Z” off the front of his name. 
How about those hydrogel moisture beads? You can buy them in the garden or hardware store, they’re added to the soil of potted plants. (It doesn’t really work well, BTW). But if you soak them in water they expand. You can also cut up an unused disposable nappy (diaper). Details here: Experiment Library for Kids | Science Experiments | Steve Spangler Science You could label it “Instant Ice” as it makes the water added to it seem solid.
Steve might have some other cool ideas.
Strictly an outdoor spell:
“This white pill can turn an ordinary bottle of pop into rocket fuel.” Drop a Mentos into a 2-liter Coke/Pepsi. If he hasn’t seen this one yet, this is where Mama Wiz can [del]have some fun soaking the child in cola[/del] demonstrate her powers.
Note: The pop in question really does need to be Diet Coke. Regular Coke barely does anything when Mentosified. And no, I’m not really sure why that is, but I’ve verified it experimentally.
^ Why does that NOT surprise me? 
Srsly, thanks for the tip. Spell-dom is in your debt.
If you can find some phenolphthalien, mix some with water and a bit of household ammonia. Keep it in a bottle. When outside the bottle, the ammonia will evaporate out of the solution, and the fuchsia color will disappear. Disappearing ink!
OMG, I haven’t thought of that in 45+ years, since I had a chemistry set as a pre-teen. I remember something about lemon juice being used for “un-invisible” ink–you would write your secret message in LJ and pass it over an open flame and it would appear. Or the paper combusted. Feel free to correct my memory.
Thanks to all recent suggestions; will tot up points tomorrow as today has been pretty well used up with birthday festivities including a trip to the local taco restaurant finished off with a lovely burp flan with a birthday candle and a chorus from the waitstaff. And a margarita for the mum… Phenolphthalein, eh? Hydrobeads? I can’t wait!
Do you or a friend have a hot tub or a pool? Most folks that have one have containers full of test strips. Drip them in the water and the pad turns different levels of color, based on what you are testing for. You could go with either a single item test strip (pH, or chlorine, or salt for example). Maybe call it a test for magic residue.
My chlorine test strips turn shades of purple. The salt test is a rusty brown.
Or you could go for a multi-test strip, and make up a different scale for each of the tests. My multi test strips test for 5 different things.
Oh, yeah, I did that as a kid. Totally freaked my mom and sister out as I was doing it at the dining room table and they were convinced I was going to burn the house down. Nope. That’s why I had appropriated mom’s big ashtray (seriously, this thing could have doubled as a serving bowl) to drop burning paper into. Actually, I didn’t set that many of the invisible notes on fire, just the first one or two while I worked out the optimal distance from the candle flame. Science! Experiments! More Science! bwa-ha-HA!