Firstly congratulations!
UK perspective
[name_f]Sophia[/name_f] is a popular name ranking at #12 in the UK popularity charts with [name_f]Sophie[/name_f] ranking #48 so both are popular well established choices. Personally I wouldn’t muddle the names up they feel very different with [name_f]Sophie[/name_f] having a more cottagecore relaxed feel (similar to J@ck) whereas with [name_f]Sophia[/name_f] feels more elegant, with a pan European flair so I can see the difference. It’s a shame the names are muddled up and being are not respecting that [name_f]Sophia[/name_f] & [name_f]Sophie[/name_f] are different.
Still I think baby name regret especially within the first year of your child’s life is really common. I named my daughter [name_f]Lilia[/name_f] had decided her name before she was born yet after she was born I felt I made a mistake. I struggled with people mispronouncing her name, misspelling her name and as a result I felt awkward introducing her. As a new mum I felt I made a mistake renaming [name_f]Lilia[/name_f] her name what helped me was establishing a nickname which I felt comfortable using with the public. So she goes by [name_f]Lily[/name_f] a lot with the general public and as [name_f]Lily[/name_f] is so recognisable it’s made my life easier. Could you do something similar maybe use a nickname like Fi to have more distinction from the whole Sophie/Sophia debacle. I also created a pros and cons list so I could fully assess [name_f]Lilia[/name_f] and my thoughts surrounding the name. I would do a similar setup for [name_f]Sophie[/name_f] so you can fully understand the name and your thoughts surrounding [name_f]Sophie[/name_f]. Maybe also try out different names and which potentially you feel better work for your daughter. I would assess this whole situation until you feel more certain surrounding the name change which I did with [name_f]Lilia[/name_f] and realised I chose the right name for her.
Honestly though I wouldn’t feel any sort of way about changing Sophie’s name it’s not embarrassing/awkward it’s completely fine to change her name so if you feel that’s right go for it.