it could mean your dead mom's spirit is trying to communicate with you.
Neurons firing randonly
Your dead mother is talking to you? Is that what you mean? She's letting you know she's there, she's okay, and she still loves you.
Maybe your subconscious is trying to tell you that there is something in your life that needs to be cleaned up. A messy relationship, a job left undone? Your mind is channeling a mother figure as a way of encouraging you to actually pay attention to the message