How did Sadie know...
...that Evie was going to end up in that yoga class?
So she enrolls in this prenatal yoga class under false pretense, and kept going regularly (she tells Evie she laughed the first time the women did that chanting thing to her, so that wasn't her first time), all in hopes that Evie would randomly end up there and they would become friends?
Most unbelievable part of the movie! Other than that, I quite enjoyed it.