Hi there, I was wondering if you had looked into the name and possible language as a way of finding relatives? Was her English, when she said her name in hospital, spoken as if it was fluent or mother tongue? From doing a bit of research into the origins/meanings of the name Kofi (and the common other spellings), we might be able to narrow down our search to a particular group or culture within Ghana, and her name might tell us more about whether or not she had older siblings, was born from a marriage and much more. It could be helpful to spread the word about her in different Ghanaian languages and French.
To look further into the above, I’d recommend contacting a suitable expert from a university.
