Star,
Congratulations on producing a fine garment that your son will enjoy "because my mom made it."
As a southpaw, I have become ambidextrous in the world of machining and mechanics. Very few large scale machines were designed with the lefty in mind, I too have developed some right handed capabilities other than the one inflicted on me as a young lad concerning the proper way to write. (Sister Steel Metre Stick). The training helped on the rare occasions that an injury took one out of service the other was trained and ready. Leftys do really have it better. I knit and crochet left handed, as well as do most of my hand stitching left handed. My machine sewing and patterning is almost always right handed. ( I rarely visit my sister, who has the only left handed machine that I know of.)
I am learning the pipes right handed from a fellow lefty.

Cheers