Sarah Chalke has her spirits up high with a son who was diagnosed with Kawasaki disease a year ago. Promoting her ABC show How to Live with Your Parents (for the Rest of Your Life) earlier this month – which unfortunately has just been cancelled – she revealed the last film that made her cry.

The mom to 3-year-old Charlie revealed to People recently, “Toy Story 3. At the end when all the characters are together. You don’t expect it to get you, and then bam! My son [Charlie, 3] was like, “What’s going on?” Oh, it’s just allergies.”

Chalke explained Kawasaki disease – a rare and sometimes fatal autoimmune illness – to the magazine in March.

“It’s a very visual disease. It’s a high fever, and then everything because of inflammation goes red. So it’s red, bloodshot eyes, red lips, red rash and red hands and feet, and then the last telltale sign is the skin on the fingers peels back. It was absolutely the hardest thing I’ve ever been through, and there’s nothing in the world like not knowing if your kid is going to be OK.”

Wanting to teach the subject on-air – she decided to play a mom dealing with the disease in an episode on Grey’s Anatomy. 

The actress shared, “As an actor, you’re usually like, ‘Will I be able to cry when I’m supposed to cry?’ But this is more like, ‘Will I be able to stop crying when I have to stop crying?’ I didn’t know what that experience was going to be like, to hold a baby that was made up to look like [now 3-year-old] Charlie did at that time.”

However filming the episode was “a really good experience” and added “the Kawasaki doctor we dealt with said they do a news story every year, and often that saves lives. She said that this [Grey's Anatomy] episode absolutely is going to save lives. It’s going to save some kids.”