After being told it was probably just a small port wine birthmark, Julia, 39, and Simon, 42, thought nothing of it.
But over the weeks and months, the smudge began to spread and grow outwards.
And by the time Lottie was a toddler, the smudge had transformed into a tennis ball-sized growth that prevented her eating, drinking – and smiling. But it wasn't just uncomfortable – the growth was painful, too. It burst twice and caused serious infections.
On top of all that, strangers would point at the little girl in the street – and one even threw a £5 note at her in pity.
It was only when Lottie refused food that doctors diagnosed 36 haemangiomas – blood vessels that grow into benign but painful tumours.
Aged two, Lottie had her first laser surgery which helped the tumour on her mouth to fade and her final plastic surgery last year.
Now, after years of pain, insults and countless operations, all the brave seven-year-old is left with is a tiny scar. Julia, from Northampton, said: "Now she has normal lips like me, which is what she wanted.
"She's confident and happy, with no side effects from all the strangers' nasty comments. She's an amazing girl."
Julia recalled: "People shouted horrible things. Someone even threw £5 at her in pity. To me she was gorgeous but I hated the staring. The operation was Lottie's choice. She said, 'I want normal lips like Mummy'."
Simon added: "She's matter of fact. She's never complained."
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