Dear Mom,
I thought you would want to know that your sister, Rachel passed away on April 4th - no one told me, I just decided to look her up online this week because you passed away 6 years ago yesterday and I was thinking about her being the only sibling left in your family and the only remaining aunt of both you and my father (all uncle having passed away years ago).
I didn't forget you yesterday but have mourned you nearly everyday since you've been gone.
We miss you more with eatch passing year.