For a number of years, the name Yamilex has been spiralling downward in popularity. In recent years, continuing the trend, the number of babies given the name Yamilex has dropped significantly.
Re: Size of full shirt decal for Gilden kids shirt. General image (imprint) size parameters for standard youth tees is 7-9 width. Height is the same. 11 shouldn't be a problem but I wouldn't go taller. Youth extra small is limited to 5-6 for a comfortable placement.
Back designs should be placed using the center crease and four inches down from the center of the neckline. There are several very useful websites out there with even more specific shirt decal placement tips.