Написать 3 предложения так чтобы получился рассказ используя все слова (was writing, was sitting, was having, had bought, had flown, had started, sold, thought, understood)

I was writing a letter to my grandma while my sister was sitting on chir and hiving dinner. I wrote a letter to her because I want to see what she had bought from France but then i understood what she had flown to Egypt and I had started to write a new letter. Also I thought  to tell grandma that we sold our old sofa, but then i understood that she don`t need to know this.