An unexpected choice, but JRN is a decent actress. She's not who I would have thought of as Claire, but there are certainly worse choices they could have made. And I like that the picture TV guide chose of her is one where she looks like she's not wearing a ton of makeup and she's not wearing something that exposes a lot of skin. She looks very classy to me. I wonder though if they will have her dye her hair for the part though. In the picture Mac showed Reed, Claire was a brunette, but Jamie has auburn/red hair.
As for the age, there isn't that much more age difference between them than there was between Grissom and Sara, and a lot of people (not me) liked that pairing. :shrugs: Also, there are A LOT of real life couples who have a lot of years difference in their ages. I have relatives who are married to people several years older (or younger in some cases) than them and they have pretty successful relationships. So it is somewhat realistic and does happen more than one would think.
As for the woman in the picture that Mac showed Reed, she may not have been available to do the scenes. Heck, for all we know, that could have been a picture that came with some photo frame LOL. And those people may be hard to track down and even if they do track them down, they may not want to be involved with acting.