Mary is only mentioned in five books of the Bible.
And there are no interceding saints or angels either mentioned in the Bible.
True! In one account, when John kneels before an angel to glorify him, the angel immediately corrects him and tells him they are all co-servants, and to give worship only to God Almighty. (Revelation 19:10)
And even in the role of mediator, nor Mary nor the "saints" have any Scriptural support.
"For there is one God and one mediator between God and human beings, Christ Jesus, himself human". -1st Timothy 2: 5 (Today's New International Version)