Stephanie was a character from the 8 webisodes, Another Desperate Housewife.
When she found out about her husband, Lance having an affair, she confronted her best friend, Elsa, not knowing what to do. Elsa tried to assure Stephanie that he wasn't having an affair, but Stephanie couldn't trust him, so she got Elsa to go and spy on him that night.
Elsa called to say that he wasn't having an affair and that he was telling the truth, but Stephanie somehow got a picture of Lance sleeping with Elsa, which forced her to make Lance choose between the two of them.
When Elsa and Lance waited to shoot Stephanie, Stephanie sent a message to Lance to make Elsa think he was seeing someone else; which made her shoot him, killing him. When Elsa was being taken away by police and Lance was being taken away by an ambulance, she and a police officer started to flirt and she gave him her phone number.
It is presumed she left Wisteria Lane as the house she lived in is now owned by Renee Perry.