I would guess many people are unfamiliar with the name and would pronounce it ay-OH-fee or ay-OIF. Is there any way you can work the pronunciation into your book? You could have the character have to pronounce it and then your readers would pronounce it correctly. I read the entire harry potter series as a kid saying HER-mee-oyn instead of her-MY-oh-nee because I was unfamiliar with [name_f]Hermione[/name_f]. That was before I became a name nerd 
Ee-[name_f]Fa[/name_f], although before I knew the correct pronunciation (I had to look it up on YouTube) I pronounced it ayf.
I pronounce her Ee-fah. If you wanted readers to be sure on her pronunciation, you could have the character sound it out like @namelover0711 suggested. J. K. Rowling actually added in [name_f]Hermione[/name_f] sounding out her name for Krum in Goblet of [name_m]Fire[/name_m] for that very reason :).
Ee-fah 
beautiful name
I’m from the east coast of the US too, but I’ve lived in [name_f]Ireland[/name_f] for the last 3 years.
[name_f]Aoife[/name_f] is an incredibly popular Irish name (I personally know at least 15 in my college).
It’s pronounced EE-fa.
[name_m]Prior[/name_m] to moving over here I thought it was pronounced like [name_f]Eva[/name_f].
Seconded. If you want to use it for a character I would also advise spelling out the pronunciation.
I can’t for the LIFE of me pronounce Irish names. [name_m]Just[/name_m] absolutely no clue, despite being a well educated, fairly worldly, name-obsessed person. They are just so, so strange to me and no matter how hard I try I cannot remember how even the common ones are pronounced. Many sound beautiful, but the spelling is just so “off” from the sound to my ears that there is no way I could figure them out.
EE-fah - gorgeous name.
Ay-Fah. Which I know is wrong but my mind just says it that way.
Interesting how many of you knew it! It might be worth while having a pronunciation guide in it I think, I don’t think I could work a pronunciation into the story, though its not a bad idea.
AY-fuh. I’ve looked it up before because I like it so I already have somewhat of a knowledge on how to pronounce it. But honestly i probably still have it wrong. Otherwise I would have no clue, being an American. It’s still a pretty name.