So happy she found you.
She needs a dental with anesthesia. They will get under the gums. No product can come close to properly dealing with this. Brushing daily is important, but that alone won't work.
She will likely lose some teeth. The longer you wait the more she will lose.
There is an anesthesia thread in the YT Library. Make sure preop blood is done. this is so extensive that her organs are probably very angry because of the amount of bacteria.