- You may be looking for an imprinted personality of a similar name, Susan Pierce.

Susan was a young girl who was orphaned early and became an identity for Echo in the first season episode "Briar Rose". She is portrayed by Eliza Dushku and Hannah Leigh Dworkin.
Background
Susan was orphaned early when her mother died and was left with her mother's boyfriend, who made use of her by becoming her pimp. She was eventually placed in an orphanage but her traumatic past and severe abandonment and isolation issues as well as her self-esteem caused her erratic behavior. She would keep knives to protect herself and was not very fond of the character of Briar Rose, tearing apart the books of the story whenever Briar Rose's tragic condition was mentioned, causing her to react violently.
Echo

Topher gave Echo the imprint of an older, mature and recovered Susan, a "best possible future", as part of a pro bono engagement to help the girl. Echo comes to the orphanage, telling the story of Sleeping Beauty, only to be interrupted by Susan, who disapproves of the story altogether, and critiques its portrayal of hapless women. Echo eventually confronts Susan and talks with her about the feeling of being helpless and abandoned. She also guesses that Susan is keeping a knife. Echo states to a social worker that Susan's healing process will be slow but she is coming close to moving on from her traumatic past.