Sally Major had been diagnosed with advanced bowel cancer in May 2015 and underwent emergency surgery, 20 cycles of chemotherapy and other self-funded treatment in the UK.
The 33-year-old's final hope was to begin a programme of treatment at a clinic in Germany, which uses immunotherapy drugs not available through the NHS.
It meant her family remortgaging their home in Silsden, near Keighley, and selling their car to raise funds.
But it was only through the support of thousands of well-wishers, who donated more than Â£70,000, that she was able to continue receiving treatment when the family's money ran out last month.
Earlier this week, Mrs Major's young children were urged to say their goodbyes despite signs that the treatment was beginning to work.
The moment they had all feared came last night when Mrs Major passed away at the Hallwang Clinic, with her mother and husband by her side.
Her husband, Liam Major, broke the news to the family's supporters this morning via a Facebook page set up to share their story.
He wrote: "It breaks my heart a little bit more than it already is saying this, but my amazing, gorgeous, courageous wife Sally Jayne drifted away to a better and more peaceful place last night whilst me and her mum squeezed her with immense amounts of love.
"Whilst the treatment was working, her kidneys couldn't handle anymore. The doctors and nurses here tried absolutely everything and have been brilliant.
"Never have I met before or will I meet again anyone so amazing, my soulmate, penguin, the absolute love of my life, and the perfect mum to our beautiful and strong kids. She'll live in them forever.
"Sleep tight babe, you deserve a rest, and we'll have a chat later, love you infinitely forever and a day, your penguin xxx."