The Famous Five series of children's books by
Enid Blyton contained a character named
Dick who had an aunt named
Fanny. And this seems to have been fine in the 1940s to maybe the early 60s, but as Using Rude Words became more frequent, kids began to snigger. And there's a lot of controversy in fandom, apparently, because these names and others have been updated/sanitised in new editions:
Fanny could I suppose be
Frannie and
Dick could be
Rick. That kind of thing. Some traditionalists prefer the originals, of course.
So, yes. I've known lots of
Frances people but they were always
Fran. And
Richard becomes
Ricky or
Rick where I live. I would be surprised to find either
Fanny or
Dick used as full names, even a century or so ago, but I've been surprised before. And if I named a child
Frances, I wouldn't use a nn; same with
Richard. I just like the full forms better.