 Charlie wants to enroll baby Owen in pre-school, but he must be potty trained before they will except him. Meanwhile, Claudia is missing Kirsten so much that she begins making up stories of disaster to get her to come over to the house. Justin s pretty British friend, Allison, arrives in town from England for a visit and she and Julia get along well, until Allison eventually shows her true sexuality when she makes a pass at Julia. Also, Bailey finds Sarah s real birth mother, a struggling actress named Robin Merrin. But Bailey doesn t tell Sarah fearing that she will be emotionally troubled again.