A spelling question

I would like to know how to spell the phrase: La-D-Da or La-T-Da. We are in a ladies group and we just named ourselves the "La-D-Da Sisters", but we are now having a difference of opinion if we spelled the phrase correctly. Some think the phrase has a "T" and some think it has a "D" in the middle. What is correct?

According to the dictionary, "t" will not be served:

la-di-da also la-de-da
adj. Informal
Affectedly genteel; pretentious.

interj.
Used to express disdain for something viewed as pretentious.

La-di-da is far and away the most usual spelling in the UK. An odd thing to call yourselves; it's not often seen as complimentary.

DFG

La-di-da was Annie Hall's catchphrase in the 1977 movie by Woody Allen. She would sing-song it whenever she didn't know what else to say.

"La di da di da di da..." is how Professor Harold Hill demonstrates the "Think System" in The Music Man.

Sounds OK for the name of a ladies' club to me.