Ce (third-person pronoun) is non-specific to gender and number.
There is no direct equivalent in English. So we have to choose between he, she, it, that, they, these, those.
Select the one that best describes the subject and the situation.
In this case, you're talking about a girl, so the best choice is "she", in my opinion.
Of course, your opinion might be different. If they're emphasizing a specific blonde girl, you might translate it as "That (or this) is a blonde girl.