1. Phonetically closer to the English pronunciation:
* Стефани (Stefani) - This is the most common way to spell it, keeping the "f" sound and a "ni" ending.
2. More "Russianized" spelling:
* Стефания (Stefania) - This uses the "f" sound but changes the ending to "-ia", which is more typical of Russian feminine names.
Both spellings are valid and acceptable, and you can choose whichever one you prefer.