NET
12 When Peter realized this, he went to the house of Mary, the mother of John Mark, where many people had gathered together and were praying.
Darby
12 And having become clearly conscious [in himself], he came to the house of Mary, the mother of John who was surnamed Mark, where were many gathered together and praying.
KJV
12 And when he had considered [the thing], he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying.