Actually "on Feb 8th A.D. 1930, Pope Pius XI, through a rescript issued the Santuary of Our Sorrowful Mother, Portland, Oregon with an Ecclesiastical feast day, to be annually celebrated on Mothers' Day, the second Sunday of May."
The feast was to be call "Behold Thy Mother".
Taken from the book Cross=Annunciation by Father Ambrose Mayer, OSM who also built the shrine to Our Mother of Sorrows. At 9 years of age Father received a Miracle from Our Mother of Seven Sorrows and the shrine was the fulfillment of the promise made to her if the miracle was granted.
I believe the story is on the shrine website. The miracle happened in my home parish in Canada in 1892.
I don't believe it's sentiment to honour our Blessed Mother today. She deserves it more than many earthly mothers.