Áinle is indeed a male name (most famously borne by one of the sons of Uisliu in the story of Deirdre in the Rúraíocht or Ulster Cycle). It goes back to Old Irish áindle or áinnle and would appear to mean something like "warrior" or "hero". As far as I know there is no female variant, but traditional Irish names don't tend to have male and female versions anyway.