From the experts:
Letitia is a delicate, once prim and proper sounding name whose staid image has been unbuttoned by numerous phonetic spellings. The original, often used in Spanish-speaking families, would still make an attractive, delicate choice. After a solid century on the Top 1000 list, Letitia fell off in the early 1980s and has not yet returned.
Letitia has a First Lady heritage, as the wife of President John Tyler. Letitia Baldridge, White House social secretary to Jacqueline Kennedy, was often known as Tish. These days, most parents would prefer the sweet, gold-locket pet forms Letty or Lettie.
Spelled Laetitia, she was the Roman goddess of celebration, happiness and gaiety. The name appeared in the form Lettice in medieval England.