Lady Scott and her husband were sitting in their living room when a golden child sized rocket containing an alien baby entered their mansion and landed right under their Christmas tree. Lady Scott found the pod and, thinking the baby was a gift from her husband for her, adopted him while Lord Scott didn't pay much attention to her.
Her comment on the baby being a "thoughtful" present implies that Lady Scott loves children and had been wanting one of her own for awhile.
Lord and Lady Scott have a present under their Christmas tree labeled "To: Bobby, From: Sally". Implying that Lady Scott's name is Sally.