The belief is perfectly biblical.
Acts 17:10 Then the brethren immediately sent Paul and Silas away by night to Berea. When they arrived, they went into the synagogue of the Jews. 11 These were more fair-minded than those in Thessalonica, in that they received the word with all readiness, and searched the Scriptures daily to find out whether these things were so. 12 Therefore many of them believed, and also not a few of the Greeks, prominent women as well as men.
Even after listening the an apostle speak they were commended for not taking his word for what he said. What he said over a period of a few days I believe, but they went to a subset of the bible, the OT, to verify that what he said was true. It's beautiful how the NT is so well contained in the OT. Now lets try applying that same commendable test to Marian doctrine. If you did, you'd leave the RCC for it's obvious heresy.
True devotion to Our Lady is commanded by Christ Him self. What is the 4th commandment and what did He tell John and us at the Cross? "Mother behold your son, son behold your mother" has far more meaning than a simple recording of a sentimental adoption. How many words in Scripture are wasted or pointless? Would God wast time with idle chatter as He hung on the cross? Doubt it.