Stephanie is nice enough.
Ticks all my boxes, including being well known enough that people won't say "What?" when you giv your name, but used fairly rarely so there won't be lots of people with your name in everything you every go to. Easy to spell and to read off a list
I don't think 'Stevie' works, but you can call her what you want in your own home., although 'Steph' is what everyone else will call her.