She screams into the phone that her daughter's damn car smells liek a dead body, she screams that her granddaughter is missing, she then removes only apair of grey pants and a knife, but leaves other items in the car, she takes those items and washes them, she and George search their backyard (for what?). She holds these items and gives the washed items to LE days later.
I think after she realized what was going on - Dead body smell + missing granddaughter + crazy sociopath of a daughter + maggots and flies + foolish story = murdered granddaughter, but it was too late as she had already called th epolice many times in order to SCARE Casey into apologizing and telling her where Caylee was, not once realizing the horror until later and that is when CA and GA instantly switched gears, protect our family and our daughter.