Mom captures moment 3-year-old boy comforts his terminally ill baby brother

PERTH, Australia -- A mother of two shared a heartwarming and heartbreaking moment between her two sons while on vacation -- and it has since gone viral.

Sheryl Blanksby posted a photo on ">Instagram of her 3-year-old son, William, telling his baby brother, Thomas, that “everything is OK.”

Thomas was diagnosed with a malignant rhabdoid tumor at 11 weeks old in February, according to Fox News.

https://www.instagram.com/p/BRT6vnjBHCr/

“#Throwback to when we were on our holiday. I was getting ready in the bathroom and husband was in the kitchen,” Blanksby wrote in the caption on March 6. “The kids were quiet, especially Mr. Preschooler.

“You know the rules about when kids are quiet. I tiptoed to the lounge with my camera ready to catch anything they are doing. I was expecting my baby to be covered in Nutella or something but instead I saw this. My preschooler is telling his baby brother “Kuya (big brother) is here. Everything is OK."

“The irony of life has hit my family so hard and everything doesn’t make sense anymore,” Blanksby posted on March 4. “It feels like only yesterday when I posted about giving birth to our Rainbow Baby Thomas and here I am writing about his imminent death.”

The family doesn’t know how much time they’ll have with baby Thomas, but plan to make as many memories as possible.

“Watching my two sons together is a dream come true,” Blanksby wrote. “Being a family of four has always been part of my day dreams. It’s now my reality and it’s trapped in this nightmare no family should be in.”