Sorry to be obnoxious, but this use of fortuitously as an all-purpose synonym for fortunately or happily or thankfully really gets on my nerves. Fortuitously means “by coincidence” or “by accident”, or sometimes “by happy accident”. The creation of Readability did not happen by chance. (Though of course, through long and increasing misuse, the word is now often used as you use it here).
Unless the parent was being ironic e.g. "its raining on me - well by pure chance they invented this amazing invention called the umbrella" (I suspect not as knowing Readability exists is not expected, though this ironic use is probably where the convergence of the terms began).
Thanks. You're right - fortunately would have been a better choice.