You can find Cookie in the bottom right corner of Parverhill. Depending on how the event goes, she'll open a portal to the Magicspirit either right there, in the top right behind a building, or in a prison cell below the fort in Parverhill.

Afterwards you can only get back to the spirit by using the Teleportstone Amagal.

If you met magic spirit where cookie took you use teleport stone from key inventory you get from magic spirit get to her