The "Girl Who Is Going To Be Okay" meme is based on a video made by comedian Caitlin Reilly in which she shares the "POV" of that character—a woman who is clearly grappling with something and then finally can process it and move on, all in the space of ten seconds.
The video is very funny in itself, because Reilly perfectly captures a well-worn yet obscure trope from movies and TV. Actors have to show growth rapidly sometimes and Reilly hits all the facial gestures, frowns, and smiles in rapid succession.