Why do Catholics say they pray to Mary as Jesus' mother, to intercede for us? I've heard that on FR more than once from, especially women, who say that. Mary can't help. Only God through Jesus can.
A couple of reasons why I, as a Catholic, believe and pray to Mary for her intercession.
Firstly, because I need all of the help that I can to get into heaven I ask people that are close to Jesus to pray for me. Mary is the Mother of God, Mary and Jesus shared the same blood. Mary was entrusted by God the Father to care for Jesus, His son. That is a pretty big responsibility and an enormous role that Mary fulfilled perfectly. Jesus listens to his Mothers' petitions.
Secondly, when Mary stops helping, I'll stop praying to her. I have a funny feeling this wont be happening anytime soon.
God Bless!