Thanks for the tip, Shaun/Jimmy. I’ll try to include that in the next version. It’s not quite so simple, though, as accented letters, apostrophes, and hyphens are acceptable elements in a name (e.g. Siân O’Reilly Smith-Klein), and the site already indicates the necessity for pronounceability and the use of the Latin alphabet.
You have no obligation to accept your employee’s deed poll, given that she’s not met those criteria, as far as I am aware.