I live in Texas which is pretty humid too.
I try to avoid brushing my hair in any way, even in the shower. It keeps the curls from aligning on their own. The most I do is use my fingers to detangle during conditioner. If there are really hard knots or my fingers are sore/injured, I have a wide tooth comb to spot treat tangles.
Personally, when I shower in the evening, my hair is always a mess the next day. I've never had luck keeping it from being a medusa mess the next day. If I want my natural curls for something that day, I shower during the day and let my hair air dry after plopping, or I partly diffuse to set in some curls to let the rest air dry.

Hey girl!

I have wavy/curly 2a/2b hair that’s gone 90% gray before 30, so I empathize with the nonstop frizz. I have a few suggestions, but take them with a grain of salt because even though it’s been years since starting CGM, I still haven’t found my perfect routine & product combo. But i’m getting there.

Unfortunately the best thing for your hair (ime) is to move to a dryer climate 😅😅😅 Humidity is my #1 enemy full stop.

Comments on routine:

1. I found it pointless to oil just before showering it right back out. Oil should be the very last step out of the shower to seal all that goodness in.
2. Reduce your usage of fingers in the shower aside from praying/squishing. Also replace any plastic combs/brushes with hard rubber or smooth stone combs. Plastic ones have hard ridges in between each tooth - These will rip up your hair as you run them down. Idk about brushes, I only use combs now, sparingly.
3. This might be huge — are you using clarifying shampoo each time? This will strip the fuck out of your natural oils and you won’t have enough time to build up enough defense for it. I’d advise not doing this more than 1-2 times per month. Find a good low-ingredient shampoo to use in between! (3b.) Just in case: only use the shampoo on your roots/scalp, keep all the natural goodness in your mids & ends.
4. Deep conditioning is good! I keep it to 1x/week though. For reference I wash my hair no more than twice a week, I prefer going 4 days in between, as that gives me enough time to develop natural oils.
5. A suggestion: maybe find a lighter leave-in? The weight of all the products together after a wash can add up to a mess, although this depends on how your hair normally reacts to light vs heavy product. ~~(5b.) How many products post-shower, and in what specific order do you use them in?~~ (nvm that’s answered in 6, sry) This can make a difference! In my experience, Lightest to Heaviest thickness is best, followed by an oil. (5c.) Cotton is def the way to go, but a lot of the time I much prefer to air-dry start to finish - Sometimes if I take too much moisture away too quickly with a shirt, it makes me way frizzier after using one! 😵‍💫
6. Continuing from 5b, I can’t say much about styling sprays (I just don’t prefer them ☺️) but I would suggest adding a detangler between your leave-in and spray maybe?
7. My only suggestion here would be a dryer that can blow cold - the less heat the better to combat frizz. No comments on the rollers, but could the foam material possibly be causing issues?
8. Yes! Good stuff 🤩

I’d also suggest looking for a shop/stylist nearby you that carries Olaplex stuff! The #6 is good for protecting from heat and keeps frizz down too. I use that as the first step, and the #9 as the last step. I think the #9 is amazing and a must-get to combat frizz! Just my 2c (edit: Whoops!! switch these around, i went to take a shower and realized i got them backwards lol)

Of course with all these things, YMMV!!! These are just things i’ve learned that worked for me, but could be not the right fit for you!

I forgot to mention previously that something we use are shower filters. I have no idea how they might affect your hair but hard water dries my skin out. I can't imagine it being great for hair. I'm just guessing on this though.

I don't see the problem. This is absolutely beautiful hair. I really love the curls too. But if you are not happy with it, have you tried washing it much less often? Unless she is styling in a way that requires "product", or it got very dirty with something, my wife might only wash it once per week.