Lisa Flynn (left) and Rihanna
is thrilled – and grateful – that the leukemia-stricken New York City mother of two she came forward to help has found a bone marrow donor
"There are no words to express how happy I am for Lisa [Gershowitz-Flynn] and her family," Rihanna tells PEOPLE exclusively. "I am so thankful she found a donor and I feel honored to be a part of such an amazing miracle."
Last month the Grammy-winning singer put out a plea for help
, and Flynn, 41, who learned she has an aggressive form of cancer called Acute Myelogenous Leukemia the day after Thanksgiving, quickly found a donor.
"This blessing has continued to keep me aware of how precious life really is," says Rihanna. "I will be praying for Lisa and her family as they move into a hopeful future."
As PEOPLE reported exclusively, as soon as Rihanna heard about Flynn's plight, she lent her name to the campaign. As a result, more than 5,000 PEOPLE readers contacted DKMS, the world's leading bone marrow donor center, to become potential donors.
Even better, DKMS recruited and registered roughly 2,000 new donors, Katharina Harf, executive vice president of DKMS, told PEOPLE.
Flynn is now awaiting a bone marrow transplant.
"My life will be saved because of you, my family and friends (old and new)," Flynn wrote in an e-mail to supporters. "My children (Michael, 5, and Alexandra, 3) will have their mother, my husband will have his wife, and my parents will have their daughter. Please continue to spread the word about how important it is to fill the bone marrow registry with donors to save others."
For more information on how to help, visit GiftforLisa.com