I assume that's your daughter?
It can be hard to really evaluate pictures of close family & loved ones. Because you know them so well, you read a lot more into the expression. If they are always smiling, but you catch them when they aren't...then it's unique and different. If they don't smile a lot and you photograph them not smiling, then you know that it's just 'them being themselves'...to you. But when you get outside feedback on those photos, that type of thing is completely lost on the viewer, and they must evaluate the image on it's own merits.
Of course, photos of family etc. will always have more meaning to you, and it's more about those feelings, than about being a perfect portrait.