Simplify the following text for a Grade 9 native English-speaking person.
Original: In a May 7 , 1918 letter from Tobolsk to her sister Maria in Yekaterinburg , Anastasia described a moment of joy despite her sadness and loneliness and worry for the sick Alexei : `` We played on the swing , that was when I roared with laughter , the fall was so wonderful !
Simplified: On 7 May 1918 , Anastasia wrote a letter from Tobolsk to her sister Maria in Yekaterinburg . In the letter , she described a moment of joy , even though she was sad , lonely , and worried about her sick brother Alexei : `` We played on the swing , that was when I roared with laughter ( laughed loudly ) , the fall was so wonderful !