I like [name_f]Posy[/name_f]! 
She’s got a bright whimsy to her.
[name_f]Posy[/name_f] it’s just sweet and emphasises flower power 
Posy is my favorite, as it seems like the correct spelling, but Posie is also a cute spelling for a nickname.
I think [name_f]Posie[/name_f] is the best!
I think [name_f]Posy[/name_f] is my fave but like [name_f]Posie[/name_f] too!
I seem to be in the minority but [name_f]Posey[/name_f] - this is because [name_f]Posy[/name_f] seems too short like the name is cut off too early and [name_f]Posie[/name_f] seems like it should be a plural. So [name_f]Posey[/name_f] looks the most complete to me.
ie names don’t usually gain my favor often just because I think that group of letters at the end looks so messy when it does not have to. Example: I’d rather have the [name_f]Rosy[/name_f] spelling over the [name_f]Rosie[/name_f] spelling