The constraint is always raw material. She has no shortage of ideas or time in which to put them into practice. Hence, she is most avaricious in acquiring hearts whenever an opportunity presents itself. Having a stockpile means she need waste as little time as possible.
"So you haven't done any more of that while you were waiting?"
"I figured far-scrying would be a good lesson for you to learn."
"What's the trick?"
"It's easier with a reflective surface. A mirror, or a still pool. There's one we passed, though."
And, on the way to it, she explains first how to project your desire into your medium, so it becomes a receptacle and reflection of that desire, and how to correctly shape a desire for scrying on someone.
Then when they reach the pool, Shade will attempt to scry the associate of the man she wants to kill. To find whose going to lead her one step closer.
She gets a watery image after some trying.
The man seems to currently live in a tent, rich wall hangings surrounding him and numerous rugs beneath his feet.
It's hard to make out much more, and the image is still, lifeless.
She needs better than that. This won't lead her anywhere if she can't see. She loops her frustration into the magic.
That gets her a soundless view - but it's clearer, and continual. The man appears to be conducting some private ritual involving incense and chants, though there's no sound.
Can the Yew Queen see this?
"Seems to be one of their religious rituals - humans have some quite fascinating beliefs in things not entirely provable to be true, and they believe there's higher powers whose favor can be brought with appropriate sacrifices."
"Is there any actual power in it?"
"I haven't been able to figure that one out!"
She wants to pull back to a broader view of his surroundings.
That's harder, but eventually she'll get an encampment of a number of tents - about ten easily visible - on some kind of low plain. Pulling back farther is hard, but it seems to be past the foothills in the mountain range's rain shadow.
"So he'll have friends with him."
"Perhaps! Or perhaps we can set a trap for him, or ambush him at a choice moment..."
"We'll need to observe for longer to figure out patterns of movement."
"Likely so, and we're not set up for a portable scry. Still, many communities are prone to scattering when they hear our horns, if you wish a louder approach."
"I prefer to keep this hunt quiet, as much as we can."
"Very well. That changes some of the mechanics - and will make certain people less likely to ride along. Still, a silent hunt will be an interesting challenge."
"Somewhat a change from your usual approach."
"It's good to shake things up, now and again."
"Are you suspicious of me?" she asks after a moment, tilting her head a bit.
"A little. Wouldn't you be?"