That doesn't work either.

Her next text to Bella reads:

Hi. Turns out printing diagrams, edited or drawn in MS Paint, doesn't work. Also there are weird things going on in the medallion incants.

Rats.

Weird things?

First one I've known about for a while: I got four diagrams off the medallion and seven incantations. I think I know which diagrams go with more than one, but things enchanted with photocopies of the same one show up as two.

Maybe there's a way to recharge a diagram or something.

If a smaller or simpler diagram can be used to recharge a bigger or more complicated one, it would save me so much effort. Maybe I'll try that next.

It would also be cool if a big complicated diagram could recharge itself at the same time as another diagram though.

Yeah. Anything that can help mass-produce medallions is worth a try. 

The other weird thing is in the last incantation. It refers to "the healing magic currently being done to the medallion", says that magic should be redone in various circumstances.

And that doesn't show up as another diagram?

Nope! And the previous one isn't a heal either. I'm confused.

Some species have non-runecasting magic.

Yeah, maybe this will need to be a team effort. I'll look up which species can do healing.

Good luck!

Margaret doesn't go to the library immediately. Nor does she start in on diagram recharging. Before she does any more runecasting, she's going to get a better understanding of her dragon powers. She makes a largeish light+control diagram, puts a rock on it, and incants, "Cause this rock to glow red for three seconds, and then to glow red for three seconds every time the person touching it does any magic other than by saying an incantation and using a diagram."

The rock glows red for three seconds, flickers, and then resumes glowing red. It continues to do this with the every three second flicker as long as Margaret's touching it.

Maybe using her medallion to pass for human counts as using magic, rather than the medallion doing magic to her. Maybe touching the detection rock counts as using magic. She can test the first one by going fullform in her bedroom and taking her medallion off for a minute.

The rock quits glowing when she does this.

At least it isn't recursive. Still, dragon fullform is not the most convenient for doing science. She disenchants the rock and tries again: "Cause this rock to glow red for three seconds, and then to glow red for three seconds every time the person touching it does any magic other than by saying an incantation and using a diagram or by using a medallion."

The rock glows red for three seconds and then stops.

And if she enchants a different rock to glow and then disenchants it, that doesn't set the detector off either, right?

It does not.

Okay. Now for the important test: what if she repeats one of the failed incantations from her experiments with light colors, one that did nothing but used up the diagram?

Three seconds of red.

Yup, she's definitely been using dragon magic to avoid dying of science. But now at least she can tell when something will be safe for her to teach other people. If medallions ends up blocked on her needing to recruit a member of some obscure species, maybe she can pick up the bags of holding project again. 

Just for completeness, she repeats an experiment that did nothing and didn't expend the diagram.

She is not doing any hidden magic then.