IF WE HAD to honor one mother above all others today - a mothers mother, as it were - who takes the cake and the roses too, it would not be a national leader, but rather a sweet and simple brunette who at this very moment lies abed in a crypt, and who for all her sweetness and simplicity, may be the most remarkable mother of our time. We are speaking of Diana Palmer, or Diana Phantom, the wife of the comic strips' Phantom, who last week gave birth to twins.

Well, not exactly. Last week she gave birth to the girl twin. It was the week before that she gave birth to the boy, or mahngahlee, which is Bandar for "little man." It took Diana an entire week to deliver both twins at which the pygmy poison people went wild with joy, yet that is not the most remarkable part of the tale, by a long shot.

For that we must turn to the Phantom himself, the mysterious hooded figure of justice whom cartoonist Lee Falk brought to life or something, in 1936.The Phantom has always looked to be about 35 years old, or 40 at the outside (at least what we can see of him in his costume does). But in fact he is part man and part legend - "the ghost who walks" - and is said to carry forth a tradition of crime-fighting that began in the 16th century. Even if we're talking about the tail end of the 16th century, we're talking about a 380-year-old father. A man who keeps a grey wolf as a pet is no one monkey with; but a father at 380 is more than part man.

Yet Diana is more remarkable still. Even if she was a mere 20 in 1936, when the Phantom started courting her, she would be 63 today. Moreover, the Phantom and Diana were only married in December 1977, which means that their courtship lasted 41 years, which in turn says as much for Diana's patience as the twins do for her courage. All's well that ends well, of course. And we wish the proud parents much joy. Yet when we think of Diana giving birth in a crypt, looking as good as she does at 63, and married to a man who has lived most of his 380 years in a leotard - now that is motherhood.