Simplify the following text for a Grade 8 native English-speaking person.
Original: Though Diana , Princess of Wales was commonly called Princess Diana after her marriage to Charles , Prince of Wales , it was officially incorrect , as Diana herself pointed out , because she was not a princess in her own right .
Simplified: When she divorced , Diana Spencer stopped being Princess of Wales , but was given the title Diana , Princess of Wales to show she had once been married to a Prince of Wales .