You'd never know that just earlier in the week, she underwent chemotherapy.

"She's definitely meant to be here for some reason," mom Sarah Walton said.

When Ellie was just 4 months old, doctors discovered a brain tumor the size of a third of her brain.

Less than eight hours later, she had her first brain surgery.

"They didn’t really give her much chance," Walton recalled. "They said basically we'd be extremely lucky for her to make it out of surgery."

The little girl who doctors didn't think would ever walk or talk has defied all odds.

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Her tumor has mutated twice into very rare forms of brain cancer.

She's had 17 surgeries and is on her eighth round of chemotherapy and radiation.

"Most of her life has been spent in a hospital," Walton explained.

But now postcards are giving Ellie a window to the world.

"Now she's getting to, just through a picture, to experience a little bit about every place," Walton added.

Her mom put the call out on social media.

So far, Ellie and her big sister, Ava, have received about 150 of them.

For Walton, it's about more than just postcards.

It's about Ellie's future.

"I just want her to grow up," Walton said. "I'd love for her to experience these places, but even more, to live to see tomorrow."

Ellie's first taste of the world comes in April when she goes to Hawaii to swim with the dolphins thanks to the Make-A-Wish Foundation.

There's also more good news.

Ellie's mom says her latest scan showed the tumor is shrinking.

If you would like to send Ellie and Ava a postcard, here’s the address:

Prayers for Ellie Walton

PO BOX 5094

Spanaway, WA 98387