I am so sorry.
Your thoughts of your mother and what she would say are so sad, and so true. I know that is the first response many JW's would have. It is a judgemental response rather than love and affection. Don't let it weigh you down. You know the only reason the bible mentions that there were deaths at two birthday parties is because details were important and that happened to be when it happened. If it had been an anniversary party, it would have listed that occasion.
I am so glad you parted with a hug, laughs and sweet memories. That is very fortunate. Much love and comfort to you and your family in the days and years to come.