Question about Glutathione and Autism?

My 2 1/2 year old autistic daughter was diagnosed 1 year ago. I started her on the GFCF diet within 1 month of her diagnoses with promising results. She was responsive and not in her own little world. I then added a multivitamin, cod liver oil and a probiotic. She was doing great after that. She had less stimming, very playful and extremely happy. She had great eye contact and was responding to her name about 90% of the time. I was getting happy. Then about 2 weeks ago I started to give her fish oil and Oral Reduced Glutathione (to improve language). I am giving her 1/2 of a capsule mixed into her milk. Each capsule contains 500mg, so she is getting 250mg daily. Since I started her on it I have noticed a regression. She is in her own little world more often, she is less playful, she is very crabby (she cries a lot), She wants to be alone more often, and now I notice she has eye squinting. She has never did that before. I was wondering if anyone experienced any of that before? Could the regression mean that the Glutathione is working or should I discontinue use? I am confused and I have not found anything information the the internet. Thanks for your help!!!