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41 And his parents went every year to Jerusalem, at the solemn day of the pasch,
42 And when he was twelve years old, they going up into Jerusalem, according to the custom of the feast,
43 And having fulfilled the days, when they returned, the child Jesus remained in Jerusalem; and his parents knew it not.
44 And thinking that he was in the company, they came a day's journey, and sought him among their kinsfolks and acquaintance.
45 And not finding him, they returned into Jerusalem, seeking him.
- Luke 2:41-45

The Lord's parents (the Blessed Virgin Mary and Saint Joseph) took Him to Jerusalem when He was twelve.

And seeing him, they wondered. And his mother said to him: Son, why hast thou done so to us? Behold thy father and I have sought thee sorrowing.
- Luke 2:48

The Blessed Mother clearly refers to Saint Joseph, so he must have been alive.

But what is most interesting is that there is no mention of any other children and the reason for that would be that there weren't any. You see, the Virgin Mary and Saint Joseph's sole focus was caring for the Son of God.