A former débutante from an illustrious family, she was jailed for passing a fraudulent cheque in 1951 and her best-known works were based on her experiences in prison.
She was convicted at the Old Bailey in 1951 and sentenced to 12 months imprisonment; though the Daily Telegraph's obituary claims "...she was naïve enough not to realise that the cheque had been forged".
[4] At the latter, she came under the care of Anglo-Irish prison reformer Mary Size, who she later described in her 1952 book Who Lie in Gaol as "a mixture of discipline and humanity.
The book was the basis for the film The Weak and the Wicked (1953), directed by J. Lee Thompson with Glynis Johns playing a character based on Henry.
It continued Henry's focus on the justice system, depicting the effect on the upper middle class family of a man accused of gross indecency,[9] and became the first play dealing with homosexuality to be approved for performance by the Lord Chamberlain, who had lifted a ban on the subject the previous year.