One of the things I hate most is when authors give their characters accents resulting in sentences that are hard to read. Even worse create cognitive disruption when reading.  The author has one character constantly use "gyal".  Which most likely would not be comprehensible to any native English speaker.  I did a search on the internet and found "gyal" is a Jamaican Patois slang term for "girl".  There is no reason to use this spelling since the vast majority of that characters prose is normal US English.