I dont normally go for high fashion roleplays, but this plot and the characters captured my attention. So I'll give it a go. :P
No, Pen isn't her real name. But humans don't have the vocal structure to pronounce hers and it was her first english word. Pen is a shapeshifter, which doesn't actually mean she can look like anyone at the snap of her fingers. It takes about a day and if very painful, so she only uses it when she is life threatening situations. Meaning she has had to change alot more than the average Kraxian in the company of the Doctor. Not many have seen the Kraxian's true form, they are a seceretive race that lives thousands of miles below sea level on their water covered planet. 'Secretive, not mean' Pen likes to say. Pen herself is a strange one, able to find peace and happiness even in the darkest of situations she is the definition of an optimist. She has faced death and darkness many times but it doesn't damper her spirit. Thats probably why she was invited along, when your the doctor an optimist is just what you need.
Abbey Lee Kershaw
+If you asked Pen if she likes swimming, she would give you a blank look and ask what such a thing was. Kraxians don't swim, they walk.
+Pen has a large family, seventeen of them in total, which is average for a Kraxian family.
+Since her travels with the Doctor, she had never returned back to her true Kraxian form.
+To her species the Time Lords where only myths, a little like her own species.
+A literal translation of her name sounds a lot like, 'Karnis', but even that is far off her actual name.