Thought Question

So, I started a series last week that I'm calling "Jesus In Jeans"* The basic gist of which is this: How to we imitate Christ in this world?

Anyway, with next Sunday being Mother's Day, I figured something along the lines of "How Did Jesus Treat His Mother?" would be appropriate.

Now for the question portion of the post: When Jesus was on the cross, why did he give his mother over to be cared for by John, since he had four stepbrothers?

-----
*Inspired by a sign I saw for a "casual worship" service, entitled "Jesus 'n' Jeans"