Ugh, I am totally plagerizinb off TMBS but...

In the perilous journey, Reynie had to figure out a way to tell the difference between real and fake (plastic) diamonds. He ended up throwing them in the water because, he concluded, the fake diamonds would float. 

Have her do something like that, where she has to authenticate something. Probably shouldn’t use gemstones... but something where the reader is lik “OHHHHH, I SHOULD HAVE THOUGHT OF THAT.” You know, like use prior knowledge almost everyone has.

Sorry, that’s all I got... 

Hmmm... maybe, since Morrowmist is with her (I love your book, by the way!), ther can be a chamber with a table of herbs and ingredients, and Morrowmist get's pricked by dragonsbane or something, and Zoey has to save her using her brains and her magic?

Hello, Starseeker! Although I have not read your book, it sounds amazing! 

So, what I'd suggest is, if this is okay, doing one or more tests for each category: mental, physical, and magic.

I don't know what time period or genre your book is, but this is my general idea for a fantasy story type thing:

For physical, you could maybe have her do a training type obstacle course or something, where she would have to defeat monsters, people, or any such thing (with a sword or something), get through thick and dangerous woods, jump distances, and eventually come to a certain part within an amount of time.

For mental, I think the idea about diamonds is really cool. Also, you could have someone ask her the answers to riddles, sort of like Golem in The Hobbit. You could also combine physical and mental, and have a treasure hunt-like endeavor. She would have to use her brains to figure out the clues leading to the treasure, and her physical strength to get across dangerous/difficult areas.

For magical, you could make her have to summon some magical tool listed in the prophecy. Once again, since I haven't read your book and have no idea what it's about, this is probably way off topic and not helpful. But, depending on what the prophecy is about, you could just draw from that. If it says something particular about who the hero is, have her use magic, or brains, or physical strength to show that characteristic. If the prophecy said that she was going to save something, have her flex her magical muscles and begin to develop her magic in ways that can help save whatever it is that needs saving.

I'm really sorry if this isn't helpful. And now I want to read your book.

Where could I find it?

:)

Stargirl! 

Hmm. I haven't read your entire book yet (though I really want to) but I have a suggestion. Idk whether it would be in magical or mental strength (probably mental) but you could have your character go through a maze of illusions. There could be illusions of monsters, or of her worst nightmares, or something similar. Kind of like that one part in Star Wars where Luke fell into that pit and fought an illusion of who he thought was Darth Vader, only to unmask him and discover it was himself. 

Is that cliche? I don't know. Now that I think about it, it sounds a bit like Divergent...oh well.  

Thanks to everyone who's posted so far! Sorry I haven't said anything before this, but my Thanksgiving break just started a few days ago and I've been relishing having nothing to do. 

@unsuspectingstrytllr: Hey, that's pretty good! I've had several people suggest soemthing to do with illusions. Good idea!

@Quill: wow, that's amazing! 

@Stargirl: thanks for all the suggestions! Thanks for reading by the way. I always appreciate it! 

@Jarvis: yeah, a lot of people have said stuff about illusions but they're all different and cool! Thanks so much for the suggestion!

FINAL DECISION:

I'm kinda combining Quill's suggestion and Stargirl's physical suggestion into the main basis of it. So, the Elder Spark has taken Chamarys and incapacitated her-- with poison maybe? And that's the incentive for Zoey to finish within one hour. If she doesn't, then, Chamarys dies. It was going to be Morrowmist but she's important to the Elder Spark and the Blaze, because she is one of the rare few who can navigate the In-Between. Zoey will have to use her physical and mental abilities to not only find her using clues written on Chamarys's scales (as proof that they actually have her), but get through obstacles on the way-- deep pits, and a room full of poisons that she has to choose the right one, and riddle-rooms, and definetely a room full of reflective surfaces that hide all sorts of nasty surprises. Thanks, y'all, for inspiring me to do this!

Many thanks,

~Starseeker