No, I realize that Stone is probably "post virgin" (no pun intended) and as of now maybe a bit overripe for Kelly.
Yes, I saw her as a blonde, although, perhaps you described her otherwise and I missed it.....been a while since I read the book.
But she seems (in the later books in which she appears as too minor a character for Stone to consider playing) to have "blonde" characteristics....in the better sense. Rather like the Loni Anderson character on "WKRP." Don't make the mistake of thinking she's dumb just because she is blonde and beautiful.
It says a lot about Marian's personal sense of self that she is able to have Kelly for a best friend, too.