I could easily turn the question around and ask you the same.
The point being, no where in the OT or the NT is Mary called the Ark of the Covenant. It is an allegorical attemtp by the RCC to eleveate Mary to something she is not based on the text of the Bible.
She isn't called the mother of the second person of the Trinity but she is. Just as the Ark contained the Father's word so did Mary. Sorry, John wrote there were many things not written down, I accept that.