When a big ship passes by, it leaves behind a trail of waves: this trail is the ship's wake, or wash. Smaller boats left behind are tossed up and down in the wake. In the paragraph, she must have been like a big ship, and as she passed by she disturbed these creatures, leaving them with knowledge.

It would be what someone or something left behind as they go. In this case she left behind knowledge.

"in ones wake" means within a person's surroundings or within contact. So "She passed knowledge to every creature in her wake" means "She passed knowledge to everyone around her."

wake = 弔喪守夜

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