[Because the girl is sweet and kinda flighty (in an endearing way), Buffy straightens out her expression for a moment.]

Look, Heart? This place isn't a walk in the park. [The recent murders sit heavily upon her mind.] So that whole looking out thing? Consider it official. If you need anything? Just shout. Preferably in the direction of a journal, so I'll actually hear. [This ends in a slow smile; after all, Buffy's main identity was one of a protector. Although it sounded rather sentimental and specific in the moment, it was the kind of service she wishes she could be more active in providing to everyone.]

But--journals. Someone's explained those to you, right?