I don't like this spelling: either
Susannah or
Susan would be better. Of the two, I prefer
Susannah.
Suki, spelt Soekie, is one of the standard nicknames for
Susan etc in Afrikaans. I prefer it to Sannie. Sukey or
Sukie was fashionable in English, according to something I read long ago, when tea was still unusual and exotic. The nursery rhyme '
Polly, put the kettle on, we'll all have tea! Sukey, take it off again, they've all gone away!' shows this, and also shows that at that time - 18th century? - tea rhymed with away instead of with sea.