BlueRose
I've read similar stories to yours. Mostly they are from people who have written letters to intuitives who have their own newspaper column.
The upshot is this --- most likely your mother is coming around because she wants your foregiveness. Sometimes when people die they cannot cross over, rest peacefully or do the work needed to move on until they've resolved unfinished business on the earth plane. If you do feel her presence again, and you have forgiven her, then speak out loud and tell her that. If not, talk to her and tell her how you feel. You may find that it is easier to express your feelings now that she's passed.
For example, my mother passed away 10 years ago. She was a narcissist and alcoholic who was verbally, emotionally and sometimes physically abusive to us kids and our father. When I became an adult, I tried to speak to her about what our childhood had been like for me and how it felt when she treated me that way. Her response was to yell at me and tell me I was making this all up! So...I never did get any closure from her when she was alive. Since she has passed on I have spoken to her when I've felt her presence. I tell her what it was like for me and I tell her that she knows and understands all this now that she is in a better place.
I have a friend who is intuitive. When I told her what I've said out loud to my mother, she got goosebumps. She told me that my mother now understands and is very sorry and wants my foregiveness. I admit this is a tough one for me, I struggle with that but am working on it...