Simplify the following text for a Grade 8 native English-speaking person.
Original: In the 1990s , it was suggested that Maria might have been the grand duchess whose remains were missing from the Romanov grave that was discovered near Yekaterinburg , Russia and exhumed in 1991 .
Simplified: In the 1990s , it was suggested that the grand duchess whose remains were not in the Romanov grave might be Maria .