許慎 writes for 媛：美女也。人所援也。
I am inclined to translate 人所援也 as ‘someone who attracts people’, but I might be mislead by English ‘attractive’. It sounds so modern. (Being a beginner with CC, I also wonder: did I get 所 right?)
許慎 himself defines 援 as 引也 (to pull). Kroll (A Student's Dictionary of Classical and Medieval Chinese) has (I) (1) pull up, pull on (a) take in hand, take by hand; draw toward one; e.g. 援筆 take up the writing-brush (2) pull along, lead on, guide (a) cite, adduce (b) recommend; appoint (3) resort to .... (II) (1) aid, assist ... (p. 576).