Everyone has their own preference, what might be big/small to one person, may not be to someone else. If she's able to deal with it, and it's not affecting your relationship adversely then I wouldn't worry about it.
I am a woman. My name isXXXXX is it that you want to know exactly? If you're asking if 10 inches is too long, I would say the same thing, it depends on the woman. Let me know if this is what you want to talk about?