Imprisoned by Herod Agrippa, just prior to the ca. CE 43 Passover, Peter awaited trial and summary execution at Jerusalem. For several days the Church of God, known at that time among themselves as the qehal'el, had engaged in fervent prayer, in this case group prayer, for his release (Acts 12:5). Peter, well-known in Mary's household, late at night goes directly to her house as a matter of course on his escape from prison (Acts 12:14) to inform the group assembled there of his release and to request that they so inform James [understood to be the brother of Jesus (Mark 6:3)] and others. Her son John Mark, later the author of the second Gospel, is a cousin, in the sense of a cousin first removed, of Barnabas (Colossians 4:10) which would make her either the sister or sister-in-law of one of Barnabas' parents. At this time John Mark was probably in his early twenties. The basis of this inference is the account of John Mark, presumably about himself when about 10-12 years old, concerning the presence of a certain "young man" who escaped naked from the scene of Jesus' arrest in CE 30 (Mark 14:50-51). See John Mark.

Her house, a meeting place for Jesus' followers inside the city walls of Jerusalem, is of special interest. It apparently had a convenient location, an entrance-way separating the main house from the street, and a room large enough for many people to assemble. These factors favor its later evolution into a house-church and a center of life of the early church at Jerusalem. Later writers believed the house, which supposedly escaped the destruction Titus brought to Jerusalem in CE 70, was atop Mt. Zion and a meeting place for Jesus' disciples from the time of the Ascension to Pentecost (Epiphanius, de Pond. et Mens. c. 14; Cyril Jerusalem. Catech 16 [note 35]). Today many believe that this site is that of the present day Cenacle and the pseudo Tomb of David but the archaeological evidence is inconclusive. If the site of the Cenacle is the basic location of Mary's house it would have been, as one of the highest spots in Jerusalem, a prestigious location. The archaeological evidence regarding the Cenacle site would require the destruction of the original structure in the aftermath of the First Jewish Revolt.

The legends persist, and they are merely myths, that Mary's house was the venue of the Acts 2 Pentecost events, the upper room where the disciples stayed, and the upper room of the first Christian Passover. The derivation of these myths apparently is from the observation and speculation of Gentile Christians, particularly the Byzantines, concerning the practices of Judeo-Christians in their synagogue on Mt. Zion, now the site of the Cenacle, then known as the Church of the Apostles. The two groups were not in fellowship with each other. Today the Chapel of the Holy Spirit in the Cenacle and countless tour guides perpetuate these legends. Tour guides, poorly informed but well-meaning, consistently explain to thousands of Christian pilgrims and other tourists that the Cenacle is the traditional venue of these events. In fact the group met on the Temple Mount in one of the rooms available for public meetings and there is no evidence that either of the "upper room" locations were at Mary's house or at the venue of the Cenacle. For a general discussion of these matters in the context of the Cenacle and its traditions see Cenacle.