Gender

I noticed that the author(s) use the pronoun 'she' as opposed to 'he' in a lot of examples. They (the authors) are both men. And the examples are not specific to women. I know its equality and all that...but it is still an interesting choice to make, and it makes me wonder which one of the two made it.
examples are:
The real estate agent on page 7 is given the pronoun 'she'. The description of her job is slightly more feminine, though. "She sizes up its charms, snaps some pictures...writes a seductive ad."
The political candidate is a man, perhaps to keep in style with all the candidates referenced (Arnold Schwarzenegger, Michael Bloomberg, Jon Corzine, Howard Dean, Steve Forbes etc), who were male.
On page 25, the waitress is a woman (duh), the Wal-Mart payroll manager is a man, the third grade teacher is a woman.
Okay I change my observation to an accusation of subconcious sexism..
The cheating teacher is a woman. However, the authors write that "male and female teachers are about equally prone to cheating." (p. 35). So why not switch up the pronouns? - (I suppose that might confuse the reader) but otherwise...
The sumo wrestlers are male, and that is logical.
So three options:
1. The authors are subconciously sexist
2. The authors like to alternate their pronouns to maintain equality
3. They have no idea they've done this at all.
Enjoy guys!