The text on her apron reads: "GEORGIA Iron sight caliber Ieaoeps(?) barrel buster", transcribed into the Greek alphabet. It must be a reference to the battleship Georgia in Azur Lane, whose inherent skills are named "Iron Sight Caliber" and "Heavy Barrel Buster". I don't know if the picture on the apron has anything to do with the battleship, though. I first thought it was a ZOID or something.
Japanese schools teach home economics from the 5th grade, such as household economics, nutrition, and apparel. It includes sewing, in which both boys and girls learn to make simple garments such as aprons. To attract the children's interest, a manufacturer of school materials offer a variety of fabric designs that students can choose from, and the most popular among boys are dragon designs like the one depicted in this pic.