Kym Marsh has revealed her daughter had to undergo an operation on her jaw just two days before her fifth birthday.
The 39-year-old mum said Polly had a cyst removed and was put under general anaesthetic.
"She was so brave though," Marsh told OK! Magazine.
"She didn't fully understand what the doctor was going to do, but knew she was going for a 'magic sleep because her mouth was poorly'."
Marsh said she took time off work to look after Polly after the operation.
"Her face was really swollen afterwards," she added.
"[Polly] kept saying 'Mummy, my face looks horrible', which broke my heart."
However Marsh, who is also mum to David, 10, and Emilie, eight, with a former partner, said Polly is now doing well on a soft food only diet of pasta and porridge.
The mother-daughter duo have been in the news recently after Polly made a cringeworthy announcement on ITV's show Big Star’s Little Star in March 2016.
Polly was asked by presenter Stephen Mulhern what she doesn’t like about her mum.
"When she gets her boobies out," exclaimed Polly.
Marsh later offered an explanation on the show.
"When we’d have a shower together she’d go ‘mummy’s boobies, I don’t like mummy’s boobies’," the mum explained.
Read the full interview in OK! Magazine, out now.