I haven't thought much about physical characteristics. Green eyes, raven black hair, tall for a woman ... Will have to give this more thought.

Now, about the first person narrative ~ I'm so glad you asked. I tend to write in first person, but sometimes the scene I want to paint is better addressed in third person. I'm not comfortable with either style enough to stick to one so I use both in posts. Is this a no-no? Example of third person below:

It seemed to Caer as she stumbled upward among the broken stones that the tower was climbing too. Time after time she gained upon it, and time after time when she lifted her eyes after a grueling struggle up a succession of steep stairs, that mocking flicker of whiteness shimmered still ahead and unattainable. It had the mistiness of unreality, and if Grania’s talisman had not pointed steadily upward, Caer would have thought it an illusion to lead her astray.

After what seemed hours of climbing came the time when, glancing up, she saw the last set of stairs rising to the topmost point which ended at a door. She took heart now, for at least she seemed to be at the end. Every laborious step carried her nearer that lofty prison.

Pausing to wipe the beads of sweat from her forehead where her black curls clung, she caught a flash of something, out from nowhere a long slinking feline creature came. It was not like any beast she had ever seen before. Its shining pelt was fabulously golden, brocaded with queer patterns of darker gold, and down against its heavy jaws curved two fangs whiter than ivory. With a grace as gliding as water it paced down the stairs toward her.

Caer’s heart contracted. She felt her dagger hilt in her hand, which comforted her. She was staring hard at the lovely and terrible cat, trying to understand the haunting familiarity of its eyes. They were purple, like jewels.

Slowly she shifted her dagger so that light glinted down on the blade. They stood quite still for a moment, green-eyed woman and fabulous, purple-eye cat, staring at each other with hostility eloquent in every line of each. Caer clenched the dagger tighter, warily eying the steel-clawed paws on which the golden beast stepped so softly. They could have ripped her to ribbons before the blade struck home.

She saw a queer expression flicker across the somber purple gaze that met hers, and the beautiful cat crouched a little, tail twitching, lip drawn back to expose shining fangs. It was about to spring! For an interminable moment she waited for that hurtling golden death to launch itself upon her, tense, rigid, knife steady in her hand ...