One of the best known of the Irish girls' names, thanks to singer Sinead O'Connor. Though it's still in the Irish Top 100, it's no longer quite as fashionable in Ireland as Aoife or Aisling. But by now everyone in the Western World knows it's pronounced shin-aid and so would have no trouble fitting in on an American playground.
This name increased in popularity in Ireland via Sinéad de Valera, the wife of president Éamon de Valera, who was born with the name Jane, but later chose to use its Irish form Sinéad. Actress Sinead Cusack is the wife of Jeremy Irons.