More than $11,000 had been raised as of Wednesday on a GoFundMe for the family.
Sophie was diagnosed with Pleuropulmonary Blastoma, an extremely rare form of cancer that occurs in the lungs, right before her third birthday.
Family friends blogged Sophie's brave journey on Facebook and a website, Love For Sophie.
"It is with profound sorrow and a heavy heart that we share the news that our beloved Sophie passed away earlier today," the announcement on the Facebook page said.
"Our heartfelt condolences to her beloved parents, Jenny and David Spangenthal, Brother, JJ Spangenthal, Grandparents, Joy and Bobby Greenblum, Cheryl and Selwyn Spangenthal."
A funeral will be held Thursday, July 11 at 1 p.m., at Schoem's Memorial Chapel in Paramus.
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