Child enjoys great adventures with grandma by the ocean. The Great Piratical Rumbustification. David R. Godine, 1978. Thirteen very short chapters tell of unusual happenings in suburbia. The Horrendous Hullabaloo.
Selfish pirate gets comeuppance from aunt.
McCully, Emily Arnold. The Pirate Queen. G.P. Putnam's Sons, 1995. A true story of a pirate named Grania and Queen Elizabeth I of England. Jolly Roger and the Pirates of Abdul the Skinhead.