No, Susan does not get pregnant in any of the Narnia books. In fact, even though the Pevensies are in Narnia for years and grow to adulthood, none of them are ever said to have married or to have had children. Which is a good thing, because they do return to present-day England as children. The transition back was difficult enough – can you imagine how horrifying it would have been to come back to your real life, knowing you left a spouse and children behind? I thought the art work on the wall was really not all that great. If Susan’s image looked pregnant, it would have been the result of a flawed carving or just a bad camera angle.