She was just seven when her mum noticed a small bald patch on her head two years ago.
Three stressful returns to school during lockdown made her more anxious, and now she has lost all of her hair.
She and her family have raised £1,300 for charity Alopecia UK, but now they are appealing for donations to help change her life and give her back the confidence she has lost.
Her mum, Wendy Pullan, said: "At the age of seven she was bullied at school. Two girls just wouldn’t leave her alone and during February half-term, on a holiday away, I noticed a bald patch on her head.
"From then we saw doctors and got referred. Her alopecia journey began. She started to lose more and more.
"Then Covid happened and she spent six months at home off school and her hair started to grow back - until schools re-opened and she lost it all and more.
"Now she is completely hairless, eyelashes and brows have gone.
"Bonnie has always been so strong, winning awards at school, the standing ovation award for her fundraising for Alopecia UK. She won an award for Alopecia UK for her fundraising and spreading awareness.
"She’s the strongest girl I know."
Later this month, Yorkshire Hair Clinic’s founders, Hayley Jennings and Jessica Patrick, will take on the Yorkshire Three Peaks to raise £5,000 to purchase a life-changing hair replacement system for Bonnie.
The advanced, non-invasive, dermatologically-tested treatment that is 3D printed to a bespoke mould of the wearer's head.
Once Bonnie has hers, she will wear it for up to four weeks at a time before visiting Yorkshire Hair Clinic for her complimentary maintenance appointments in their dedicated private suite.
Made from 100 per cent human hair and custom colour-matched to Bonnie’s hair and scalp, the system can be washed and styled as though it were her own hair.
“As a family, we engage with Alopecia charities and remind Bonnie every day that real beauty is on the inside but the reality is we know the importance of hair to young girls," said Wendy.
"As secondary school looms, she says things to me like 'Mum, I don’t like myself' or 'Mum, all of my friends are pretty and I’m not'. It is heartbreaking to see the toll it has on her mental health.
"Having a CNC hair system would change her life, build her confidence, and rid her of the daily struggles she faces currently."
To donate towards the £5,000 needed, visit https://www.gofundme.com/f/little-hair-loss-miracles