Book one of Dark Avenger’s Sidekick. Also book 4 of Moth and Cobweb, and there are connections to the first trilogy The Green Knight's Squire, but not so much as within the first trilogy.
For one thing, we have a new main character. She is instructed by a bright lady who tells her all her oaths are void as she is returned to life, and given directions. Then she wakes up in a hospital bed with an invisible ring on her finger, and no memories. She even looks at herself in the mirror and is surprised when she speaks spontaneously in English.
Then intruders in red caps come: two werewolves and a goat-man. She can fight, but the goat-man tells her that he follows the orders of Thursday, and their fight ends with her plunging from the window with him. Then he falls faster than she does, and she learns she can fly.
It goes on, involving making a friend named Elfine who calls her Ami, iron nails and a pearl, wondering how she knows that knowing many languages is unusual, a kidnapping, stolen clothes, finding out what the hospital had about her, discovering some of what the ring can do (including attract attention), knights, werewolves and a dog disguised as a wolf, a warehouse burning down, being taxed with not obeying her oath, and more.