(NEW YORK) -- Two sisters have shaved their heads in solidarity with their mom who lost her hair while undergoing chemotherapy.
"I kept trying to discourage them," Joanna McPherson of Shreveport, Louisiana, told ABC News' Good Morning America.
She said she told them, "I don't know if you know what you're really asking to do. You hair is part of your features, your head might be cold, and other kids could make fun if you."
"They said, 'If people are going to do that to you, then we don't want you to go through it alone,'" McPherson added.
McPherson was diagnosed with HER2-positive breast cancer in October 2018.
The Air Force colonel and mom to Alexa, 11, Kayla, 10, Sophia, 7, and Jocelyn, 4, began treatment shortly thereafter.
HER2-positive breast cancers can be more aggressive than other types of breast cancer, according to the Mayo Clinic.
McPherson was first diagnosed with a different type of breast cancer and underwent a double mastectomy. Doctors later determined she had HER2.
McPherson underwent three rounds of chemo and she has three more to go.
She began losing her hair on Dec. 21 so her husband, Shawn McPherson, shaved it off for her.
Weeks later, McPherson's middle daughters Kayla and Sophia asked if they could part with their own hair in support of their mom.
The McPhersons made it a family affair. Shawn took charge of the buzzer while the eldest Kayla filmed. A tearful McPherson stood by watching.
"I never felt that strongly or passionately about something at their age," she said. "I thought I would let them express themselves as they're dealing with this pain and difficult time in their lives about what their mom is going through...someone they love."
She went on, "They have such big hearts and I just thought it was very sweet of them to make such a grand gesture of love."
McPherson blogs about experience on her site, her2positivelife.com in hopes to help other families in similar situations.
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