N.S.
It will come off, I promise! We got permanent marker off of the face, so pen should come off just fine.
Try some rubbing alcohol, it usually takes ink off of anything. If that doesn't work, baking soda and water. You might have to scrub a little bit, just don't use anything too rough. It should come off!
Be very careful NOT to get any liquid in the eyes. They can rust inside and then they won't open and shut. It's best to cover the eyes with a towel and rubber band it to the head. We do this when we're giving the dolls a hair wash.