Her last scene in the movie was before the climax. And her kiss with Strange was more like a farewell kiss than a “let’s get back together” kiss. It felt like Strange was ultimately leaving that life behind by becoming a Master of the Mystic Arts. Seems likely they will introduce Clea.
And unlike Thor, her role doesn’t have a heroic makeover. She’s a variation of Night Nurse who doesn’t have interaction with Strange in the comics.