The former Liberty X singer was recently diagnosed with having the BRCA2 gene, which carries an 80% chance of contracting the disease.
Heaton explained that if anything were to happen, she would rather her husband Hugh Hanley meet someone in order for her daughter Faith to have a mother.
"It's really difficult to say how you feel when you get told something like that," she told Lorraine Kelly.
"When you get clearly upset and your baby is laughing and giggling, you just feel things crumbling.
"If I go, will he find somebody else? The last thing you want to do is have your baby without a mum. I almost give my husband permission to find somebody else if something happens, because I want her to have a mum."
Heaton said that she is considering getting a double mastectomy and to have her ovaries removed to reduce the risk of cancer.
She also stated that her chances of having another child were low, but that she feels lucky to already have one daughter.
"I feel lucky that I found out now, rather than pre-Faith, because maybe the pressure would be too great to conceive as quickly as I have.
"I'm fortunate that I have one gorgeous child, but of course I'd love more."
On her daughter's chances of contracting the gene, she added: "She now has a 50% chance of having the gene as well. When she's 18 she'll be legal to get genetically tested. She'll have the choice to be tested."
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