Well, no; Theophania was a common Christian name in the Eastern Roman Empire. “Tiffany” is an English version of Theophania, a Greek Christian name referring to the feast day also known as Epiphany or Three Kings Day. The masculine form is Theophanes.

“Jennifer” is, by the way, the English form of the Welsh name Gwenhwyfar, also known in French as Guinevere.