To provide an answer to this question, I turned to Got Questions Ministries, accessed April 17, 2018, [https://gotquestions.org/Jesus-siblings.html]. "Jesus’ brothers are mentioned in several Bible verses. Matthew 12:46, Luke 8:19, and Mark 3:31 say that Jesus’ mother and brothers came to see Him. The Bible tells us that Jesus had four brothers: James, Joseph, Simon, and Judas (Matthew 13:55). The Bible also tells us that Jesus had sisters, but they are not named or numbered (Matthew 13:56).
In John 7:1-10, His brothers go on to the festival while Jesus stays behind. In Acts 1:14, His brothers and mother are described as praying with the disciples. Galatians 1:19 mentions that James was Jesus’ brother. The most natural conclusion of these passages is to interpret that Jesus had actual blood half-siblings."