"member of a noble family," Old English æðling, from æðel "noble family, race, ancestry; nobility, honor," related to Old English æðele "noble," from Proto-Germanic *athala- (cognates: Old Frisian edila "(great-)grandfather," Old Saxon athali "noble descent, property," Old High German adal "noble family"), which is perhaps from PIE *at-al- "race, family," from *at(i)- "over, beyond, super" + *al- "to nourish." With suffix -ing "belonging to." A common Germanic word (cognates: Old Saxon ediling, Old Frisian etheling, Old High German adaling).
<a href="https://www.etymonline.com/word/Ethel">Etymology of Ethel by etymonline</a>
Harper, D. (n.d.). Etymology of Ethel. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/Ethel