Aelf can mean elf, but also simply supernatural, which might well, in the Christianized Anglo-Saxon wold, have a gloss of heavenly. (In all those Edwards and Edgars etc, the word 'Ead' means blessed.)
I'm not sure if this is supposed to be pronounced like Elf - fled - uh (In which it sounds like 'elf fled her', which would really only make sense in some extremely obvious in morals short story), Elf - flee - duh, which sounds a bit too much like Al Qaeda, or Elf - eye- duh, which sounds like an elf named Ida, or an elf flying, or even more like Al Qaeda. Old English is really cool, and if you want to name your child or character something from the language, that's awesome, just... not this one.
It should be noted that Elfleda can also be a variant of the Anglo-Saxon feminine name Ælfflæd, which consists of the Old English elements 'ælf' meaning "elf" and 'flæd' meaning "beauty". An example of this is the 8th-century saint Ælfflæd of Whitby, whose name is also recorded as Elflaeda and Elfleda.- https://en.wikipedia.org/wiki/%C3%86lffl%C3%A6d_of_Whitby (in English) - see the entry for Ælfflæd on page 17 of "Women's Names in Old English" written by Dr. Elisabeth Okasha: https://books.google.nl/books?id=3z0-fUT70DsC&pg=PA17 (in English). [noted -ed]
I'm torn on this name. I like the association with the words 'elf' and 'fled', but it kind of reminds me of Alfredo sauce... It's pretty written but not spoken. Maybe coining a new way of saying it would help? Elf-lie-da maybe?
The name has that sound that makes it sound like someone is trying to pronounce something different but has a lisp, a burnt tongue, food in their mouth, or whatever. It's the ''LFL' combo that makes the name so bad.