I better let you guys know

Today during Kaytlin's therapy they were working on animals again. Kaytlin was saying goodbye to all the animals as they were being put away. She was down to the last two, a duck and a cow. She picked up the cow, looked at it all puzzled, then reached and grabbed the duck with her other hand and said good bye duck and put it in the bag. She proceeded to look at the cow in her other hand and then looked at her therapist, she had forgotten what it was.

I wish someone could tell me why in the world does she always lose cow? What is it with cows?? It is so frustrating that we don't know why. I am hoping it is only because of sensory. I keep saying that I don't completely agree with the diagnosis of autism simply because she shows all this progress and I think everything is working itself out, and then boom, she looses a word. It isn't like this is a first time thing either.. She even baffles her therapists. Okay rant over, sorry I am just so confused with this.