A toddler in Florida has been diagnosed with cancer after a Manchester woman saw early warning signs in a picture.
Madeleine Robb, from Stretford, who has never met her pen pal, spotted a shadow behind one of Rowan Santos's eyes on pictures from her first birthday.
She then e-mailed her mother Megan advising her to get medical help.
The toddler was diagnosed with an aggressive form of cancer - Retinoblastoma - and underwent an operation and is having chemotherapy.
The two mothers became friends on an internet messageboard after their children were born on the same day.
But when Mrs Robb saw the pictures she said she knew something was not right.
"I recognised something I'd seen in a news article," she said.
"The eye was reflecting a light but it wasn't just reflecting in one picture - but in a few of them.
"I sent her an e-mail just saying it was important she have it checked."
Megan Santos took her to the doctor the same day and her condition was diagnosed.
The rare cancer often only shows up in photographs in its early stages.
Mrs Santos said she will never be able to thank her friend enough.
"If Madeleine hadn't noticed this, we might have waited before taking her to the doctor," she said.
Mrs Robb said: "I feel blessed I've been able to do something like that.
"It's quite quite profound when you think about if it hadn't been found and the implications of that - It's quite humbling really."
Ms Santos added: "Other than an online messageboard she doesn't know me from anyone and I have to say she saved my daughter's life.
"She's selfless and wonderful. She really thought hard about sending that email and I'm so glad she did."
"I wish I could meet her and give her a hug as she's the reason we are going to have our baby for her second birthday."
The toddler will still lose her eye, but doctors have said her chances of survival are much greater thanks to the early diagnosis.