Best bet is to try to do a factory reset. I only owned one digital Nikon (besides the Fuji S1/S2 bodies) and one film Nikon. ALL of them tended to back focus. I nearly spiked one on a particularly frustrating day. Ditched the lot, went back to Canon, and with one foray into Sigma as a side camera, have been happy ever after.
Thank you I will reset it when she brings it to me.