While she initially helped Strange recover after his car accident, she left him after they got into an argument where he accused her of pitying him.
Strange reunited with Christine after he became a sorcerer, and she saved his life after he was injured during a fight with one of Kaecilius’ followers.
For those who need a Doctor Strange refresher course, Christine Palmer (who, in the comics, is one of the women who’s also known as Night Nurse) is a surgeon and Stephen Strange’s ex-girlfriend.