[Columbine]

Depends if you want a 'real' name or something more like a nom de plume. Like, the difference between naming your child 'Poppy' and naming them 'Daffodil'. The first is a real name, the second sounds like it logically should be, but is too off the cuff to actually be one.

I know 'Ran' is orchid,
'Sumire' is violet and a name(but could be a bit old fashioned), .but i think written differently
'Sakura' is an obvious one, but a bit cutsy for your character,
"Ayame" can mean Iris, and is also a place name and a given name, but i think they are all written differently.
If you want a kind of odd play on words, you could have "hachiko", but change it so that it's written 'bee child' rather than it's normal kanji. Actually, i think the normal version is 鉢 which can mean 'flowerpot.' :/ but don't take my word for it, i'm guessing mostly.

Hard to say; naming a character is a personal thing. Nothing i've suggested are really proper names, but maybe go look up some lists of names and have a think, there's plenty of websites.