But she wasn’t going to miss out on the chance to cheer on her man when he was awarded his provisional wings by his father on Friday.
Wearing a chic cream mini chiffon dress with a jacket and high heels, Chelsy didn't stop smiling as she watched the short graduation ceremony.
The pretty blonde, whose presence confirms that the couple's turbulent relationship is very much on track, was sat next to Princess Diana's sister, Lady Sarah McCorquodale in the third row.
Others at the celebration included the Duchess of Cornwall, who is still confined to a wheelchair, and Tiggy Pettifer, Harry and William's former nanny.
The 25-year-old royal and eight other training pilots were awarded their wings by Charles – the Army Air Corps Colonel in Chief.
Before the ceremony, which took place in Hampshire, the soldiers were inspected by the Prince of Wales.
Breaking military protocol, Harry went to shake his father's hand, which Charles corrected with a shake of his head before telling his youngest son how smart he looked.
Evidently delighted with his wings, Harry also received the Peter Adams trophy – a prize for tactical ability – prompting a loud cheer from his girlfriend.
Before the ceremony, it emerged that Harry, who was originally an officer in the Household Cavalry, will next train to become an Apache attack helicopter pilot, and therefore could return to frontline duty in Afghanistan.
He will begin the training course in July at the flying school in Middle Wallop, where he will be based for eight months.