It's Tessa Ferrer!
Tessa's great-grandfather is George's grandfather, so the two are first cousins once removed.
And the Gravity star isn't the only talent Tessa has in her family! Her mother is "You Light Up My Life" singer Debby Boone, her maternal grandfather is 1950s pop star Pat Boone, her paternal uncle is NCIS: Los Angeles star Miguel Ferrer, and her paternal grandmother is "Mambo Italiano" singer Rosemary Clooney (George's aunt).
Another similarity Tessa has with George? They are both former stars of long-running medical dramas. George starred on ER for its first five seasons from 1994 to 1999, and Tessa left Grey's Anatomy in May after one season as a series regular.
Hopefully, like George, she'll make occasional returns to the show that made her famous!