Yes, definitely send a thank you card. 110% send the thank you card. This is life people, you may never have been in the 'real job' world, but one of the things you do is send people (unless they are close personal friends) a thank you card for an interview or any type of assistance. If it is a close personal friend who helped you out, you take them to dinner/lunch instead. Additionally, you can try to be sneaky and leave one with a receptionist before you leave, but it is best to write it after you've had the meeting so you can include specific details of your meeting.
Oh, and always listen to CB. She knows her stuff!! (and she's über awesome)