Hello Sandy,I'm sorry you lost your mom. It sounds like you were very close. You have to understand that she hasn't left you. She's just stepped into the next room. She is still with you and is very happy and busy in her new life there. And she knows you'll be coming in in a few decades to join her and all those who have preceded you.
We don't know why EMDR has the effect that it does. Other techniques have a similar effect. Mediums can help make contact. We know that Dr. Moody's psychomanteum creates a similar effect without EMDR. Read about it in his book, Reunions.
Craig