Charles and Carley are definitely too close. Especially because you'll probably be using them in situations where you could potentially be referring to one or the other (in parenting situations).

For some people, having characters with the same first letters in their name makes it one-step more likely that I might mix them up. But it becomes a lot more likely the more letters they share. Charles and Carley share 5 letters in the same order (with an H interrupting in the former). No way I could keep them straight. Joshua-Gabe and Jeganna have enough different letters in there, and especially without sharing the first vowel, that I would have very little problem with them, though you might end up on my "author loves that letter" shelf on Goodreads.

OTOH, I do find Joshua-Gabe a little strange to call a character all the time. Then again, I have no problem with "Charles Wallace" in the Wrinkle in Time books, so I'd prolly get used to it.