Well, they exist. No one else besides Emily has ever given Edie carte blanche to read their minds whenever, but there are several other people who will say yes if she asks sometimes. Dad almost always says yes, although that has more to do with Edie knowing when to ask than Dad almost always being up for it.
...Of course, Edie can make sure to only look at some things and not others, so it's not quite the same thing, is it.