Would you do a free sonogram so that a non-profit org can get certified?

The CareNet Preg Center is looking for pregnant people that are due between June-Oct 08. They need so many people inorder to get certified. The center was the nicest people to me when I was trying to get my preg confirmed for my insurance co. My sonograms are already free(paid for my insurance), but should I let them do one for helping me out. My Mom says No, since they cannot provide medical advise.