I confess I don't grok the whole visiting a parent w/kid in jail thing (personally I'd be right out of there), but maybe he was framed, or in jail for insider trading (come to think I wouldn't visit them if they did that either). Maybe I just live on a different planet, but I digress.
Did this woman buy the book with her own money? If so, it's none of your business. You can just ask her why she gave it to him. Maybe she hopes it will help him rehab and become a more enlightened father to their child when he eventually is released from prison.
@ Sleed - wft? I (re)married a man without children. He's damned lucky to have *me* (and vice-versa). Yikes, man, what kind of women do you hang out with anyway? Wait, I forgot.. you chase underage teenagers. That would explain things.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh