A portrait of schoolgirl campaigner Malala Yousafzai has been sold at auction, raising more than $100,000 (£60,000) to improve life for girls in Nigeria.

Auction house Christie’s said that the portrait by acclaimed artist Jonathan Yeo, called Girl Reading, was sold for $102,500, topping its guide-price of $60,000 to $80,000. The proceeds will be donated to the Malala Fund.

The Malala Fund announced earlier this week that it will use the money to support Nigerian charities that are working with girls and women. The news comes as the search for more-than 200 teenagers kidnapped from their school in north Nigeria by Islamist group Boko Haram continues.

Malala, now 16, was shot in the head as she travelled home from school in Pakistan in October 2012. She had been targeted by the Taliban because she had spoken out for girls’ education.

She has recently spoken about her support for the girls abducted in Nigeria, describing them as ‘her sisters’.

In an interview with CNN last week she said: “The whole international community should think of the girls in Nigeria and speak up for them. The Nigerian government should also take it seriously and should concentrate on education and make sure every girl when going to school is protected and safe.”

Malala now lives in Birmingham with her family, where Yeo visited her to prepare the portrait.

Yeo told TES that he believed the portrait had a “quiet power” that reflected Malala’s own spirit.

He said: “The very act of painting, of creating an icon of someone who deserves it, is an important part of my job. Having made that decision, to then decide to support her organisation was logical.”

The painting had previously been part of an exhibition of Yeo’s work in the National Portrait Gallery in London last autumn.