Sydney is a medical student who is partnered up with Hen during an exercise with cadavers. she faints and is annoyed when Hen shows concern for her.
She later shows up at Hen's house to make sure Hen won't tarnish her career, and suggests Hen will not be able to complete med school.
She later reveals to Hen that she has the BRCA1 gene mutation and got a double mastectomy and RRSO surgery six weeks before med school. Her mother died at 34 and her grandmother at 32.
After telling Hen she wants to be the first woman in her family not only to graduate medical school but to live past 35, Hen nods her head slowly and says "then we'd better get to work".