Re: Struggling with daughters
If you are planning to use Sophie on a daily basis, but insist on using a longer version on the certificate, use Sophia, even if it looks funny to you. Having Sofia on there but using the Sophie spelling seems unnecessarily complicated. You're never going to look at "Sophia" again so just put it on there and forget about it.
Name her Sophia Marie Juliet, called "Sophie". It looks and sounds great and satisfies all the issues.