Context again...
Jesus is the Davidic King who rules forever. As the Davidic King, His Mother sits at His right hand as the Queen Mother--as did Bathsheba with Soloman (1 Kings 2:19).
She is also our Mother. As Christ is our brother in our divine sonship and our Bridegroom--as the Church is His Bride.
She is also the Ark of the New Covenant who bore the same elements as the Ark of the old Covenant--the Rod of Aaron for the priesthood, the Tablets of the Law, and the manna (the bread come down from Heaven). Just so is Jesus the High Priest, the Word and the Bread come down from Heaven. God's Shekinah Glory was promised to overshadow Her as it did the Ark of the old Covenant when God was present.
She is also the Mother of God (Theotokos) as Jesus said He and the Father are One.
I could go on but you see that she has many roles to play.
The husband and wife relationship is far more important than the mother son relationship and the bible is clear that in heaven we are no longer married to our earthly wives. On earth when Jesus said "Who is my mother" he puts all Christian women at the same level as Mary saying that all Christian women are His mother/sister. Therefore RC doctrine about Mary's position in Heaven is scripturally baseless.