Some time back, Eva Kiss mentioned how she sprinkles pieces of her personality across the characters she writes but that no character is a direct self-insert for her. It's typical for most writers. She addressed it several times, even during the early GGGB days when some patrons thought the Eva character was an in-game copy of the dev's real-life personality.
Also, the dev used to be more open and post more about themselves, including regular Q&As, photos, and other details about her life, but stopped sometime after sharing some selfies. I guess she didn't factor in that frustrated Stans and Arthurs are a sizeable chunk of the game's fanbase.