I’ve always liked it as a [name_f]Brit[/name_f] living in [name_f]America[/name_f]. But would it be mispronounced constantly? To me it is Cos-ihm-ah, not Kas-seem-ah. We have an Italian last name starting with a Co, so I especially like it for that reason. [name_f]Coco[/name_f] would be a cute nickname.
[name_f][/name_f]Alternatives on our list are [name_f]Camille[/name_f], [name_f]Lydia[/name_f], [name_f]Alice[/name_f] and Florence/Flora.
[name_f][/name_f]Any middle name ideas?
I think you’d get some mispronunciations, but a quick correction would sort it.
[name_f][/name_f]As for middles:
[name_f][/name_f]For more elegant,
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Seraphine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Isolde[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Delphine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Evadne[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] Vesperine
Earthy,
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Fern[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Marigold[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Faye[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Plum[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Wren[/name_f]
Minimalist,
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Jane[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Rue[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Lark[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Noor[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Blythe[/name_f]
Some might mispronounce it, but it’s a beautiful name so don’t let that stop you from using it as there will always be someone to mispronounce a name.
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Delphine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Eugenie[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Vivienne[/name_f]
I adore [name_f]Cosima[/name_f]! [name_f][/name_f] [name_f]Audrey[/name_f] [name_f]Cosima[/name_f] [name_f]Jane[/name_f] is on my own list. [name_f][/name_f] 
[name_f][/name_f]. I say it like coss (like cross without the R)-ih-mah. [name_f][/name_f] The middle I is soft like in [name_m]Kit[/name_m].
I love [name_f]Lydia[/name_f] from your list as well but it doesn’t have as much sparkle with [name_f]Cosima[/name_f] for me.
[name_f][/name_f]Here’s some ideas:
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Liv[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Tess[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Joy[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Juliet[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Eve[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Seraphine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Fleur[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Giselle[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Pearl[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Lou[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Violet[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Katherine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Odette[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Penelope[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Ruth[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Blythe[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Nell[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Zoe[/name_f]
Good luck!
I really love it for you, esp with your last name- alliterative names are my favorite and [name_f]Coco[/name_f] is just wonderful!
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Florence[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Marianne[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Alice[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Madeleine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Pearl[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Leonine[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Xanthe[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Sylvie[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Opal[/name_f]
[name_f]Cosima[/name_f] is charming [name_f][/name_f]- bright and cool!
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Luisa[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]June[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Florence[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Adele[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Pearl[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Daphne[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Edith[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Holly[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Faye[/name_f]
[name_f]Love[/name_f] the name, it comes and goes from my list just wasn’t sure about the vibes but the sound is gorgeous. I had [name_f]Cosima[/name_f] [name_f]Sparrow[/name_f] on my list 
I find [name_f]Cosima[/name_f] very pretty. But I think if you want the authentic Italian pronunciation, then in English-speaking countries it will be mispronounced a lot. I don’t think that’s necessarily a big deal though. Lots of names are pronounced differently in different countries/regions. As a [name_m]Irish[/name_m] girl living in Spain I don’t really mind how people pronounce my name 
[name_f][/name_f] but that’s just me.
[name_f]Cosima[/name_f] [name_f]Charlotte[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Violet[/name_f]
[name_f][/name_f][name_f]Cosima[/name_f] [name_f]Lucy[/name_f]