"For those of you who didn't have the pleasure of knowing Michelle, she will always be known for the love she had for her family," Herwehe said in a GoFundMe page he set up for her husband Chris and their two children Gage and Monroe.
The devastated friend said his heart breaks for her son and daughter "knowing they won't grow old with their mama".
"I can't even begin to imagine what her husband Chris and her two babies are going through," Herwehe explained.
The young mum had two children of her own. Photo / Facebook
He started the fundraising campaign to raise money for the heartbroken family. It has raised more than $US48,000 ($A70,000).
"I want to start this page to help raise money for help with the kids, for Chris as they all adjust, funeral services, or anything at all to make it as easy as we can on them," Herwehe wrote.
"You hear about these things happening all of the time but never in your life imagine it will happen to you."
Michelle left behind husband Chris and their two young children Gage and Monroe. Photo / Facebook
Herwehe said the loss of his friend "doesn't even feel real".
"Let's be there for Michelle's family like they would for us. No one deserves to lose their mama so young or the mother of their children," he said.
"She's a hero in my eyes"
Shocked friends have flooded the charity page to offer condolences and support to the widowed husband and his children.
"Chris, your loss is indescribable and so very sad. May God and Michelle wrap their love around you and your beautiful babies as you move forward. Big big hugs young man," one friend wrote.
"I never met her, but she's a hero in my eyes. God bless her family," another person said.
Others said it was "horrible" her surrogacy journey ended in such tragedy.
