In most cases, a corn will have laid all her eggs within 24 hours. If she's depositing one at a time, and acting restless, it sounds like she's not satisfied with the next box you've provided (you did provide a nest box, right?). What type of medium are you using for her to lay her eggs in? I tried a coconut fiber and peat mix one year, and my snakes hated it. The females laid their eggs everywhere except the nest box. Vermiculite works good, although its messy, as does sphagnum moss. Perhaps the temps aren't right or she doesn't feel safe/secluded enough? I try to give my females a rather tight fitting container. Too big and they tend not to use it.