Questions & Answers about Sy skryf 'n gedig.
Here it means she, because it is the subject of the sentence.
- she as a subject pronoun
- her as a possessive word, depending on context
In Sy skryf 'n gedig, it clearly means she, because it comes before the verb skryf and is doing the action.
One small spelling note: sy is only capitalized here because it is the first word of the sentence.