Her Fullname in Thai is read here,
Somdet Phra Chao Phi Nang Thoe Chao Fa Galyani Vadhana Kromma Luang Narathiwat Ratchanakharin. To call in short is Princess Galyani Vadhana. She was initially named "May" on her birth certificate, she was born on 6 May 1923 in London, England.
Princess Galyani Vadhana was a princess of Thailand and the elder sister of King Ananda Mahidol (Rama VIII) and King Bhumibol Adulyadej (Rama IX). She was also a direct granddaughter of King Chulalongkorn (Rama V). This portrait was taken when she was student at Civil Aviation.
This postcard set was full of her phto in various things she did, in remember of her good job after she passed away on Jan 02, 2008, aged 84. I sent it to serveral postcrossing member such as annekaarina and Jangalene
More about High Royal Princess Galyani Vadhana, Princess of Naradhiwas is here