Green’s Dictionary of Slang

(Ulster) a growing boy, a large young lad.

1825		T.C. Croker Fairy Legends and Traditions of the South of Ireland (1862) 312: Judy and myself, and the poor little grawls, will be turned out to starve.
1910		P.W. Joyce Eng. As We Speak It In Ireland (1979) 267: Grawls; children.
1997		Share Slanguage.