The Elite
BOSS
I know it's easy to read too much into things (look at the last few pages), and you have to be mindful of the intended audience, but referring to her father as "Luke Skywalker" seems so...impersonal. We can infer from the trailer that Rey understands BB-8, so is it too much to assume that he atleast tells her he needs to find Luke? Much like R2 giving Luke reason to seek Old Ben.
I'd imagine it's just a name to her at that point.
Well yeah, she doesn't necessarily know Luke is her father yet. So it's just same famous bloke named Luke Skywalker from a war long gone as far as she is concerned.
So yeah, BB-8 doesn't tell her everything.