I am a new chicken owner and one of my four chickens has been having some problems. She's always been a regular layer but the past too days she hasnt laid a full egg but more like pooped out 2 very very soft shells on the coop floor. Today she has been having a lot of diarrhea and is now pooping out a white foaming substance. Does anyone know what this could mean?? She's been acting totally normal before all this.