Claim: Rose Kennedy held the title of Countess.

Countess Rose Elizabeth Fitzgerald Kennedy -LRB- July 22 , 1890 -- January 22 , 1995 -RRB- was an American philanthropist , centenarian and socialite . She was deeply embedded in the `` lace curtain '' Irish Catholic community in Boston , where her father was mayor . She was the wife of businessman and investor Joseph P. Kennedy Sr. , who was United States Ambassador to the Court of St James 's . Their nine children included President John F. Kennedy , Senator Robert F. Kennedy , and longtime Senator Ted Kennedy . She was the sixth American woman to be granted the title of Countess by the Vatican .