Hi. I asked that very question to a Catholic I knew.
He explained it to me like this:
Him: You are close to your mother right?
Me: No.
Him: (Long pause)
I will never forget the look on him face when I said that.
But then he went on to tell me that most people are close to their mothers. That they run to their mom for comfort. They know their mom is a gentle being. Mother Mary is a sinless person (his words not mine. No human is sinless). So, therefore Mother Mary is the one you run to when you need comfort. She is the Catholics mother. She will talk to Jesus and Jesus will talk to God.
I don't believe any of this...this is what the guy told me.