Simplify the following text for a Grade 12 native English-speaking person.
Original: Princess Alexandra , The Honourable Lady Ogilvy , LG , GCVO , CD ( Alexandra Helen Elizabeth Olga Christabel ; born 25 December 1936 ) , is a member of the British Royal Family , the youngest granddaughter of King George V and Queen Mary .
Simplified: Princess Alexandra , The Honourable Lady Ogilvy , ( Alexandra Helen Elizabeth Olga Christabel ; born 25 December 1936 ) is the youngest granddaughter of King George V of the United Kingdom and Mary of Teck .