The Dark Brotherhood assassin with a fondness for stabbing unicorns.

Gabriella obviously isn't a Dunmer name, which means one of her parents must've been human.

But I can't decide which race is most likely the one, Breton or Imperial.

What's your guess?

Gabriella is a Hebraic name meaning God is my might. http://tinyurl.com/7v84sgk

Since it is a name used mostly in Italy, I'd go for Imperial.