Perhaps. The Scripture doesn't detail what exactly she was doing. However, one presumes that she was striken with sorrow. Knowing what she was told regarding her Son and on what she pondered upon, it is likely that she was actively offering her own motherly ties up to the Father as a sacrifice in her own sense. Most mothers would desire to hold on to her son in such a situation. The Church teaches that Mary was abandoning this concept as an incredible spiritual sacrifice on her part.
This is quite different from a person who is present ONLY in body to what is happening in another language 50 yards away. In many cases, I think people were there merely to fulfill their "duty" to appear at Sunday Mass, rather than "participating" in that one-time offering of Christ on the Cross... That is the impression I get from when I was a youngster. The reading of other books or reciting the rosary during the Mass is pretty good evidence that a person's mind was elsewhere. Recall the Scriptures teach that our inner dispositions are much more important than our outer activities. Being in the building of the Church while the Mass is proceeding is not the same thing as participating in the sacrifice of Christ on the Cross.
Regards
They were doing both. And they were going to confession before mass too. There's no better reason to go to mass than just to obey what God commands. It may even have more merit in God's eyes if it requires effort and does not give the reward of "good feelings".
The reading of other books or reciting the rosary during the Mass is pretty good evidence that a person's mind was elsewhere.
Uh, no. The "other books" were probably the missal or a prayer book for the mass with specific prayers for specific parts geared to the intellectual ability and piety of the reader to help them focus on the mystery of the Holy Sacrifice and the meditating on the mysteries of the Rosary, specifically the Sorrowful, is meditating on the Holy Sacrifice.