A breast cancer survivor organized a breast milk donation drive that has so far netted more than 4,000 ounces of breast milk for a woman diagnosed with breast cancer just weeks after giving birth.

Ashli Brehm, of Omaha, Nebraska, put out a call to her Facebook followers last month for women who wanted to donate breast milk. Within one week, Brehm had collected 4,500 ounces of breast milk.

Ashli Brehm, left, helped organize donations of breast milk for Jackie Holscher, right, who is battling breast cancer.

Brehm, a mother of three who underwent a double mastectomy last year, donated the milk to Jackie Holscher, a mother of three who underwent a double mastectomy on Nov. 3.

Holscher, 33, of Ankeny, Iowa, was diagnosed with stage 2 breast cancer in May, just weeks after she gave birth to her daughter, Genevieve. Holscher breastfed Genevieve until her cancer was diagnosed and it was no longer an option.

“Breastfeeding was something that I had done with my other two kids for two years each,” Holscher told ABC News. “I felt devastated that that was being taken away from me. I had to basically mourn a loss of not being able to nurse.”

Holscher's best friend and other local women stepped up to donate breast milk, but the supply quickly ran low.

When Holscher, who met Brehm through a mutual friend, confided to Brehm her disappointment in not being able to breastfeed Genevieve, Brehm stepped into action.

Ashli Brehm, 35, of Omaha, Nebraska, poses with her three sons while she was undergoing treatment for breast cancer.

"I just figured I can ask [on Facebook] and maybe I’ll get her a few hundred ounces," said Brehm, a blogger. "I was so overwhelmed within the first 24 hours by what people were offering and doing, I just was crying. It was like some sort of miracle.”

Brehm figured out locations to store the breast milk and picked up the donations, including from one woman who was undergoing cancer treatment herself and drove two hours from Kansas to drop off 1,300 ounces of her daughter’s breast milk.

“I had people offering to send it on dry ice from Canada and people offering freezer space at different dropoff points,” said Brehm. "It’s overwhelmingly beautiful to me what humans will do for other humans."

Brehm has stopped accepting donations for Holscher for now due to storage but plans to put out another call in the New Year.

She emphasized her motivation was less about making sure Genevieve had breast milk and more about making sure Holscher saw her wish fulfilled.

"I knew she could use formula. [Jackie] knew she could use formula. It was her wish to give Genevieve breast milk," she said. "Cancer does enough to take away from people, so I wanted to give her this wish."

Ashli Brehm, left, and Jackie Holscher pose on the day they randomly met at Nebraska Medicine's Village Pointe cancer center.

Holscher, who got approval from Genevieve's pediatrician to use donor breast milk, said knowing that she always had a supply on hand was a huge stress relief.

"It made me feel like cancer isn’t winning completely," she said. "And the donor milk has alleviated financial stress because I don’t have to think about how I am going to pay for formula and my medical bills at the same time."

Genevieve is now a growing, healthy baby, according to Holscher, who described herself as recovering "better than expected" from the double mastectomy.

"I am completely overwhelmed because it's so heartwarming what people have done," Holscher said. "When I was diagnosed, I decided I could either let cancer win and go down a depressing path or I could choose happy.

"I just decided that I was not going to let cancer win and take life away from me."