In English speaking countries, it is legal to give a child any name you wish, as long as it is spelled out in the letters of the Roman alphabet, so of course Joeycan be a girl's name. I don't know a girl named Joey personally, but I well remember the actress Joey Heatherton:
Jena is a name which has been pronounced either as Gina or Jenna depending on how the parents came up with it. The only Jena I know personally is from Iran originally and pronounces her name as "ZHEN-nah".
Joanie would usually be two syllables as "Joan-ie" in the Anglo community in the USA, but I think some Hispanics do say "Jo-annie".
Joni is usually also "Joan-ie", but there are some women with the name who pronounce it as Johnny, such as the disabled artist Joni Eareckson Tada: