Miranda is not an English name. Whoever is doing the research has it wrong. Shakespeare did not come up with the name. Miranda is an old Spanish last name. It goes back centuries, and means "worthy of admiration."
In Latin, the "nda" ending means "she must be" or "she is to be," so Miranda literally means "she must be admired" or "she is to be admired," which is just so beautiful. (Similarly, Amanda means "she must be loved")