I don't usually comment on these types of posts, but felt compelled to due to the content.
First of all, throw away the "tangle tamer". Your DDs hair doesn't need any taming, she's not a pet and her hair is not an animal. Don't use that type of language in relation to her hair either, particularly around her.
Secondly when you got the Afro comb, did you actually know how to use it? If not, start watching YouTube videos, and fast. Watch everything you can find about the way to comb any type of Afro hair to get the least amount of breakage (from the ends in, not from the root out).
You say you were managing before your DD got to 12, she was most likely tolerating how it was being done previously, and at just about to hit her teens, she has probably just reached a point where she felt comfortable expressing her discomfort.
Wide tooth combs work best with curly hair because they don't try and make it do what it's not designed to. A brush is not going to help in any way shape or form. Your DDs hair is becoming matted because it's not being looked after properly. Follow the advice given by PP, and you should be able to restore her beautiful hair again.