You'll be causing poor
Madelyn a great deal of unnecessary confusion. It'd be like using the spelling
Amy and insisting that everyone pronunce it e-MAY.
As a somewhat random note, I have a friend whose parents named her
Madeline, since it could be pronunced MAD-ah-LYNE or MAD-uh-lin--they decided she could pick which pronunciation she liked better when she was older. She's decided not to pick, and so she answers to both (but is mostly called
Maddie).
Array
"What are these parents thinking?...Let's name her Madison--she'll live in her own world: 16 square miles surrounded by reality." -- Susan Lampert Smith