As per dream meaning and interpretation, dreaming of my dead mother being alive means she has some unfulfilled wishes or she wants to convey some important message to you. It also means you have not kept certain promises made to your mother. Dreams of my dead mother alive also means there will an important change in your life near future.
If mother died of accident or something similar then seeing her alive in dream means she might have left something for you or want to you to complete some task so that she can escape from the earth plain.
Dreaming of dead mother alive and if she is angry means that you are on the wrong path with your activities or you are doing wrong things or are in a wrong friendship. They want you to change for the good. It is a warning sign.
Dreaming of dead mother alive in an unknown place means she is trying to tell you about her hidden possessions and hidden wealth. She will show you signs about them.
Dreaming of dead mother being alive is a very common dream as people usually think about her or talk about her during the daytime and such dreams have no meaning as it is an extension of daytime activities. But if you are dreaming of dead mother being alive without any daytime influence then it has some important meaning.