We don't know much of Jesus' life except for his public ministry from the age of 30 to 33. We have a few details about his birth, but the only other mention of his life before 30 is found in today's gospel when he was a teenager. It's hard being a teenager, even if you're the Son of God. So many things are changing in adolescence. There are new expectations, responsibilities, fears & feelings.
And there is often turmoil between teenagers & their parent(s). Even in the "holy" family. There was poor communication because Jesus didn't tell (or ask permission) to remain in Jerusalem while the family was headed back to Nazareth. His parents are hurt and fearful and angry. Mary says, "How could you have done this to us?" And Jesus' response? "Why were you looking for me. I was in my Father's house. It's not my problem you're upset."
The stresses in family life should not then be considered sinful. Jesus was the Son of God. Mary was born without sin. Yet they still misunderstood one another, hurt one another. Mary put the blame on Jesus. Jesus said that she didn't trust him. Poor communication, fear, worry, & blame. Sound familiar? But they used this situation for growth. "Jesus went back to Nazareth in obedience & grew in wisdom & grace." Mary "kept all these things in her heart." Our families too can be holy, even as we endure difficult relationships. As long as we are willing to grow, we're on the holy path.