The Duchess of Cambridge donned a pair of headphones and tried to interpret codes during her visit to Bletchley Park where her grandmother worked.
Valerie Glassborow worked as a civilian member of staff, probably as a duty officer, alongside her twin sister Mary.
Wearing an Alexander McQueen outfit, Kate greeted staff on a visit to mark a year-long restoration project at the Buckinghamshire site.
More top news
Ministry of Defence investigating allegations that members of the British Army shouted sexist abuse watching England Women football team.
The US space agency NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet.
Comedian Peter Kay has said he is "thrilled" to star in a adaptation of broadcaster Danny Baker's autobiography.