Why not? You'll have to enlighten us here. The woman on earth is the same person as the woman in heaven; she was his mother on earth, she remains his mother in heaven. Or if your mother is dead, do you think she is indifferent to what happens to you?
You have to be kidding. Do you really believe this? Do you really believe that God wants us to pray to Mary to intercede on our behalf? God clearly tells us to come directly to Him:
Hebrews 4:16 "Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need."
Do you actually believe that God is incapable of hearing our prayers without the assistance of Mary? Do you think that the Creator God of the universe needs any help in hearing our prayers?
I fear that your God is too small, if you truly believe these things. Or have you forgotten that God is omniscient?