Johnson Wahl’s marriage also suffered, and she got divorced in 1979. She went on to marry US historian Nicholas Wahl in 1988.
But she said that she remained on good terms with her first husband, “because I couldn’t bear not to be”, The Times reported.
While juggling family life, Johnson Wahl gained renown as a professional portrait painter. Her famous sitters included Joanna Lumley, Simon Jenkins and Jilly Cooper, although she also painted other subjects, including landscapes.
In 2015, the Mall Galleries in London presented an exhibition of her work called Minding Too Much, which chartered her “turbulent life”, including her experiences of marriage, motherhood and mental breakdowns. “Johnson Wahl paints with unswerving honesty and power”, the gallery said. “Above all, these paintings reveal a deep understanding of the complex human condition, and an empathy for our struggle.”
In the run-up to the exhibition, her friend and curator Nell Butler wrote an article for The Telegraph in which Johnson Wahl described how she became an artist.
“My older sister was terribly clever, as was my younger brother,” she said. “My parents didn’t know what to do with me so they gave me some paints and I turned out to be good at it. Once I started, I couldn’t stop.”
However, painting became more difficult after she was diagnosed with Parkinson’s at the age of 40. Johnson Wahl told Tatler that “I would spend all my time writhing and jerking”, although subsequent medical treatments helped to less her symptoms.
But despite her love of painting, “her children are, obviously, her great joy, and they are devoted to her”, said the magazine.
Her daughter, Rachel, told Tatler that “as I get older, I realise how lucky I am to have her as a mother”.
“She somehow enhances everyone she meets, and her extraordinary ability to appreciate other people – however apparently unblessed with charm or appeal – makes one see why they too are loveable,” Rachel added.
“If any of her children have any empathy or humanity – I hope not too big an if – it is largely thanks to her.”