Gluten free flours can be very different, even from one manufacturer.  For example, King Arthur has two certified gluten free flours that act quite differently in some recipes. I find that it is best to use the recipes on the website of the manufacturer of the flour, although I often bake for a shorter time than listed. I like this recipe for chocolate chip cookies: Chocolate chip cookies using King Arthur Measure for Measure gluten free flour

Thankyou so much for your replies. I have been gluten, dairy, egg and soya free for 5 years, and am mainly symptom free following an extremely strict diet but still symptoms flare up again and I have to do an elimination test to determine the cause.. basically my intolerances are still developing and I've found I can't eat: apples, grapes, raisins and other dried fruit, spinach, potato, tomato, onion, cabbage, leek, broccoli, mushroom, oily food, coconut oil, pork, sulphites, alcohol, spirit vinegar... I have difficulty breaking foods down, especially the skins of fruit and veg. I have been trying to reintroduce gluten in order to have a reliable ttg blood test, but I'm in so much pain.. abdominal spasms, joint and muscle pain, bloating etc etc, this is all from having half a wheat crispbread. I'm not sure if this is celiac or something else as there seems to be no sign of it getting any better. 

I have seen numerous gluten-free flours in stores then 1to1 cup substitute and numerous gluten-free recipes from gluten-free cooking websites that have great recipes but even making my own blend it seems like its not easy to get a fool proof flour substitute for cookies, cakes. I know bread is a bit different but this is more of a science to figure out. I have seen the flour mixes on this site as well. I know gluten-free flours tend to be pricey. What does every use as their go to for baking cookies. 

Checked into Gluten free in Aruba FB groups on places to safely eat so I hope I have a good experience in a few weeks in Aruba.

Since gluten sensitivity or celiac disease could be a factor (alongside other potential allergens like dairy, eggs, or environmental triggers), getting proper testing is key. In Christchurch, you could start with a pediatrician or GP who can refer you to an allergist/immunologist or a pediatric gastroenterologist (if celiac is suspected). For allergy testing, some options include skin prick tests or IgE blood tests (for immediate allergies), while celiac testing requires gluten consumption beforehand. If you're hitting roadblocks, consider reaching out to Canterbury Allergy Clinic or checking with Christchurch Hospital’s pediatric services for guidance. In the meantime, keeping a food/symptom diary may help identify patterns. Hang in there—getting answers can take time, but you're on the right track!