More info about the name "Mattie"
Diminutive of different names, including Martha, Madison and Matthew, but most likely Matilda. Matilda is a derivation of a Germanic name Mathildis, which means "power, might in battle". Nowadays, the name is very popular in Scandinavian countries. In the United States, it was most popular at the end of 19th century. It was popularized by Roald Dahl in his novel called Matilda.