My wife found the name [name_f]Jelena[/name_f], and we’d love to use it somehow. The only bad part is that we can’t think of a nickname other than [name_f]Gigi[/name_f] or [name_f]Lena[/name_f], neither of which we really want to use. Anyone have any ideas?
Depends on how you are pronouncing it? [name_u]Jay[/name_u]-lay-na?
You could use
[name_u]Jay[/name_u]
[name_f]Jaylee[/name_f]
[name_m]Laynee[/name_m]
[name_m]Lenny[/name_m]
I quite like [name_m]Laynee[/name_m] as a nickname or shortening but a nn can be anything my first thought was Jelly 
It seems like your wife just came across the name in print and hasn’t heard it actually said aloud, but technically Jelena is pronounced like Yeh-leh-na, not Jeh-le-na like you seem to be going for by saying Gigi would work as a nickname. (It’s an Eastern European version of Elena.) Not that you can’t say it with a “j” sound if you really want since the average English speaker probably would guess that pronunciation at first glance, but I just thought you sound know. Anyway, the only other nicknames that come to mind are Laney and Nana. (Maybe Janey or Jenny if you did use the “j” sound version?)
[name_f]Gigi[/name_f] Hadid’s real name is [name_f]Jelena[/name_f], but it is pronounced “YEH-layna”
Jela, Jelka and Jelica are traditional Slavic diminutives for [name_f]Jelena[/name_f], but I’m not sure they would wear too well on an American girl. What about [name_f]Ellie[/name_f] or [name_f]Ella[/name_f], taken from the “el” part of the name? If you pronounce it with a J sound (which I’m personally not fond of), [name_f]Jen[/name_f] is also an option.
Everything has been explained. It’s pronounced like yeh-leh-na. Some nicknames that are frequently used here (in Croatia) are:
Jela
Jele
[name_f]Lena[/name_f]
You could also use:
[name_f]Ela[/name_f]
[name_f]Ena[/name_f]
[name_m]Just[/name_m] please don’t pronounce it like jay-lay-nah or something like that, lol.
[name_m]How[/name_m] are you pronouncing it?
Jela/Yela
Jelen/[name_f]Yelen[/name_f]
[name_u]Lanie[/name_u]/[name_u]Laney[/name_u]
[name_f]Elen[/name_f]
[name_f]Elena[/name_f]
Jelly/Yelly
[name_f]Ena[/name_f]
[name_f]Jena[/name_f]/Yena