Herelgo: I'm glad to see that you are already managing and started a life outside the JW. As for your mother, well, you may send her "prayers" if you want. That is, expressing your feelings without expecting any answers of any kinds.
You know, very often, JWs will try to rationalize the fact that they are shunning loved ones by turning the responsibilities around. They'll say: It is my son who dissociated and left me by leaving Jehovah. It is not me who decided to leave him. However, if every now and then, she gets a letter from you, she will have to re-evaluate her position. Remind her of your love and your desire to include her in your family life, she will have to come to terms with the fact that it is HER and HER alone who puts a stop to your relationship. And if you doubt that she reads the letters? Send post cards with pictures of your family.
I'm willing to bet that your mom will still read the letters.