Simplify the following text for a Grade 9 native English-speaking person.
Original: The truth about Tyler 's paternity did not become public until five years later , in 1991 , when she changed her name from Rundgren to Tyler , but kept the former as a middle name .
Simplified: The truth about Tyler 's paternity did not become public until 1991 , when she changed her name from Rundgren to Tyler , but kept the old one as a middle name .