I love [name_f]Xiomara[/name_f]- I hadn’t heard this name before, but it really is lovely. I think that because of the popular [name_f]Xanthe[/name_f] and [name_m]Xander[/name_m] being pronounced ‘[name_m]ZAN[/name_m]-thee’ and ‘[name_m]ZAN[/name_m]-der’, [name_f]Xiomara[/name_f] is going to be pronounced ‘[name_f]ZEE[/name_f]-oh-marr-ah’? Gosh, I love X_____ names so much 
The nickname Xio is absolutely perfect too, and I think it will transition from a childs name to a womans name well. I say go for it!
I think it’s great. It is unique, but it has history behind it and a pretty meaning. I would pronounce it [name_f]Zee[/name_f]-oh-mara or Zho-mara. I love the nicknames [name_f]Mara[/name_f] and Xio ([name_f]Zee[/name_f]-oh or Zho). I say go for it!
I don’t thin it’s TOO crazy and out there, I like the way the ‘mara’ sort of grounds the ‘Xio’ sound, very interesting. Plus she would have the choice of the nn: Xio or [name_f]Mara[/name_f]. Yeah I think I dig it!
I with [name_m]Blade[/name_m].
Great Name but I think that unless there is a large Spanish speaking population around, or you speak Spanish at home this name is going to be difficult for most. Your daughter will most likely go by a nn for most everything and I think it’s worth considering if that’s something you’d be happy with. I assume you like the name as a whole and not just as the abbr. Xio/[name_f]Xia[/name_f].
I really like it!
I actually knew a [name_f]Xiomara[/name_f]. She was quite nasty, but aside from that, I had absolutely no idea how to pronounce her name, and neither did anyone else. She ended up going by a nickname that was unrelated to her given name.