My daughter went from being bald to having the longest curliest, most thick hair you can imagine. It's beautiful, stars pay good money to have hair like hers, but combing it is a daily drama. I personally found that "kid" detangler and "kid" shampoos were not strong enough due to the thickness of her hair and the curls (you'd have to make the call for your daughter here). We never use anything in the shower that's not Pantene, Tresume, Garnier, etc - real stuff that manages and controls her hair better between washes. Out of the shower you could try Infusium leave in conditioner instead of the detangler (put it in a spray bottle though) - it works pretty well for us, especially between washes.
The best way to avoid tangles though is as soon as she gets out of the bath to comb the hair and put it in a loose braid for her to sleep in. It works wonders the next day when there are no tangles. I know you said she hates pony's etc., but if you can get her to try it once she might find she likes it, if it does indeed work. It still leaves a challenging day if you don't wash her hair everyday, but half the drama is progress right?
I was also once told that satin sheets supposedly help with tangles. My daughter got some satin sheets for her birthday last year and loves them. I'm not sure they really do anything for her tangles, but I figured it was worth a shot. You can Google that and see what you can find about satin sheets and tangles and see if you think it's worth a try.
Regardless, girls will be girls - dramatic. When my husband combs her hair, let's just say the whining and wailing is MUCH less, so you might let him have a try at it just as an experiment. My guess is that you are right on - yes, it does hurt at times, but at others, it's entirely for your benefit. Good luck.