Was Mary Surprised about Jesus’ Deity?

{Was Mary Surprised about Jesus’ Deity?} If Mary was aware of the immaculate conception (visited by an angel, etc.), why in Mark 3: 21 does it seem she’s surprised about Jesus being the Messiah? Scripture says His "family" that goes to "take charge of Him" for being out of His mind are His mother & brothers. Why would Mary think He is out of His mind if she had been visited by an angel?