Private Practice Casts Derek Shepherd's Lil Sis

First we met Derek's older sister, Nancy, during Season 3 of Grey's Anatomy, and now his little sister is making her way to Private Practice.

Caterina Scorsone (Crash) is joining the cast in the recurring role of Dr. Amelia Shepherd, TVGuide.com has confirmed. However, she is not going to be heading to Seattle Grace just yet.

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Scorsone, 28, joins Private in Episode 19, which is slated to air in early April, when her character gets a job at Oceanside Wellness, as first reported by EW. There are no plans yet for her or her brother (Patrick Dempsey) to cross over, but it's inevitable, right?