Simplify the following text for a Grade 7 native English-speaking person.
Original: Her remains were identified through DNA testing and were buried during a funeral ceremony in 1998 at Peter and Paul Cathedral in St. Petersburg along with those of her parents and two of her sisters .
Simplified: Her remains were identified through DNA testing . They were buried in a funeral ceremony in 1998 at Peter and Paul Cathedral in St. Petersburg with those of her parents and two of her sisters .