Shakra is typically found in a dark, fog-laden cavern strung with great chains, often near a large structure with lit windows. Much like Cornifer in Hollow Knight, scattered golden rings indicate her presence.
If you can't locate her in the wild, head to the platform up-right of the wish well and strike the ring twice to call her back to camp. She returns there between expeditions while searching for her master.
Approximate position (subject to refinement)
First revealed in the announcement trailer under “New Friends”, Shakra is a warrior who has mastered a Craft-Skill — Cartography.
A later blog post describes her as seeking her master who disappeared under strange circumstances, and hints at her aiding Hornet with her cartographic expertise.
She was later directly confirmed to be the provider of mapping tools for Hornet — charts, compasses, and various other utilities.
Her in-world discovery is similar to Cornifer: scattered golden rings signal her presence; if absent, she can be called back at camp by striking the ring near the wish well.
Shakra is shown as a capable fighter: for example in the ant arena in Hunter's march, if still present, she fights alongside Hornet after the first wave, bouncing her ring to attack at range. There may be circumstances later where she clashes with Hornet.