I can't remember if she was called Mother Mary prior to Vatican II, could be because she has so many Titles, Our Lady of Fatima, Our Lady of Guadalupe, etc. just look at the Litany of the Blessed Virgin to see all her titles, plus many more.
What I could never understand is, why is it when I am praying to her, someone will advise me to pray to her under this Title or that Title, isn't she the same Blessed Mother?
Even in spiritual reading you can read that Our Lady of the Blessed Trinity was her favorite title, then in another book you read where Our Lady of ? was her favorite.
I can see your concern Raoul, and the reason is the Modernist are good at taking a truth and stretching it, exaggerating till it becomes a heresy.