Shamrock pattern template for sewing

My wife is embarking on a new adventure, sewing.  She wants to make St. Patrick's Day themed sweatchirts and asked if I could 3D print her a template for doing so.

I have no experience in sewing, aside from simple garment repairs in emergency situations but since my wife has been so supportive with my hobby I like making things to help her with her new craft.  I explained to my wife the concept I have for making such a template, and she thinks it will be good.

I've made my wife a few other templates for her sewing, and she usually uses a single piece of fabric for designs she's putting on shirts, but she's also been experimenting with a little quilting lately, so her first St. Patrick's Day sweatshirt started as a small basic quilt and she cut the shamrock shape out of it using this template.

I'm sure there are better ways of doing what my wife and I are trying to achieve here, but we're both new to this sewing thing, so any advice or criticism is welcome.