She is and she is not : a fragment of the true history of Miss Caroline de Grosberg, alias Mrs. Potter, &c. &c. : exhibiting a series of uncommon artifices and intrigues in the course of her transactions with the Earl of Lauderdale, in the years 1764 and 1765 : together with an account of the proceedings in the process she commenced against his lordship, and the substance of the evidence on both sides : compiled from papers of undeniable authenticity, and dedicated to Mrs. M--t C--e R--dd.