[name_m]Hi[/name_m] berries! I’m not having children any time soon, but I have always loved names and thought about the names for my future children. [name_f]Calliope[/name_f] [name_f]May[/name_f] is my favorite name, and has been for almost two years now. I have my heart set on using it. However, I also love the name [name_f]Caroline[/name_f] [name_f]Alice[/name_f], because it would be a honor name for my mom and grandmother (mother’s middle name is [name_f]Alice[/name_f], and my grandma’s name is [name_f]Carolyn[/name_f]). [name_f]Do[/name_f] you think using two C names, and then a different letter name for a third child would be odd? What do you think about the names as siblings?
I don’t think it’s that big of a deal. To me, sibling matching/differentiating is something that should be way down on the list of things that are important in names. Most people who know you don’t even know your siblings’ names unless you’re very close, and even then they probably don’t care if your names sound good together. The same will be true for your children. I wouldn’t give up a name you love or a name that has special meaning to you just because it has the same first initial.
I think that [name_f]Caroline[/name_f] and [name_f]Calliope[/name_f] are different enough, even though they begin at the same letter. While they are different style wise, they don’t sound that bad together.
As for future siblings, I wouldn’t expect the pattern to be followed. Maybe for daughters, but it wouldn’t surprise me to see other siblings with different letter names.
I don’t think it would be weird to have only two C names in a sibset, especially if you had two girls with C names and a boy with a different initial, for example. I usually don’t like matching initials like that, but if you really like those names, I think it’s much better to have matching initials than to feel like you have to settle for a name you don’t like as much just to avoid matching initials. I don’t think [name_f]Calliope[/name_f] and [name_f]Caroline[/name_f] really match in their style, as [name_f]Caroline[/name_f] is more classic and [name_f]Calliope[/name_f] is pretty unique, but again, if those are the names you like, then you should use them, even if they don’t go together 100%, because your kids will be their own individuals, and most of the time (in school, work, etc.) their names won’t be said/used together anyway.
tl;dr You should totally use [name_f]Calliope[/name_f] and [name_f]Caroline[/name_f] together if those are the names you love. 
Being one of two Ks in a family, it’s a bit annoying but not a huge deal. We have to use our middle initials to identify when everyone else is using just first and last. And email addresses generated by university and such let me be (first initial)(last name), but my younger brother had to have some other address (can’t remember if it used his middle or the number 2, etc). All in all not a huge deal but a minor annoyance that I’d try to avoid for my own children. That being said, if I really liked two names with the same first letter of course I’d use them. Different initials is way down the line of importance, there are many more important things to consider first.
It is not a big deal to me. There are a lot of people here that have issues with siblings who have the same initials, and that’s fine, but I see no problem with it as long as you choose names you love. For example, if [name_f]Cordelia[/name_f] and [name_f]Callista[/name_f], [name_f]Fiona[/name_f] and [name_m]Forest[/name_m], etc are siblings, I see no problem with it. However [name_f]Calliope[/name_f] and [name_f]Caroline[/name_f] share a lot of similarities on the spelling side of the subject. Although, they sound completely different, so I’m not confident that it’s too big of a problem.
I don’t think it’s too big a deal, in reality. Sometimes when it’s hypothetical, it can be really easy to over analyse everything; or at least I do. They’re different enough to work together fine, and it’s more important you love both names. By the way, [name_f]Caroline[/name_f] [name_f]Alice[/name_f] is a lovely combo, and [name_f]Calliope[/name_f] [name_f]May[/name_f] is absolutely gorgeous. I have [name_f]Anna[/name_f] [name_f]Calliope[/name_f] [name_f]May[/name_f] on my list :).
Personally I don’t think I could do it, but there isn’t anything wrong with it. Siblings won’t always be written down together. I guess you’d notice it more if you had three children, two of which were C names and one something else, than if you say, had five children, as there wouldn’t just be one with a different initial.
I think it’s just fine